As someone who works in the noise field, it's worth noting that a 1-2 dB noise difference isn't really noticeable in the human ear, 3dB difference is slightly noticeable, 5dB is a distinct difference, 10 dB difference is a doubling/ halving in noise. Definitely invest in a breaker bar for your wheel nuts, and a jack!
How can it be, that he soundproofed so much, and in the result its only about 2dB quieter? I would say 50-60 hours of work, and probably about 1,5k£ wasn't worth to get that kind of low results. I mean im after few videos with soundproofing car, and many of other cars get 2x more from just silencing doors OR wheel arch (not both at the same time). The first thing that comes to mind immediately is that, the @jamieaygo made something terrible wrong, or other videos are manipulated. @dann6341 can you tell which one is it? And sorry for poor english, not my native :)
How can it be, that he soundproofed so much, and in the result its only about 2dB quieter? I would say 50-60 hours of work, and probably about 1,5k£ wasn't worth to get that kind of low results. I mean im after few videos with soundproofing car, and many of other cars get 2x more from just silencing doors OR wheel arch (not both at the same time). The first thing that comes to mind immediately is that, the @jamieaygo made something terrible wrong, or other videos are manipulated. @dann6341 can you tell which one is it? Also sorry for poor english, not my native :)
Finally a hands on attitude for untrained but interested ppl. And you show what you do for ex the sound deadning in the wheel section. Everbody else talks about it, but nobody showed it. thanks for that, helps me a lot seeing it visually. A little side note: I would emphasize the three layers clearer to your audience, because I had to rewind a few time to get the layers right as a beginner with the project of sound deadning.
Safety: as well as using axle stands, chock the wheel on the opposite corner both front and back of the tyre. Especially when working on a slippery, loose, or sloped surface! A pair of folding wheel chocks is cheap, or if you have scrap wood around you can make your own. A lot of sound deadening is reducing the pitch of the noise - that's what adding mass to a vibrating panel does. Low pitched rumbles are less annoying than whistles and hissing noises. It may not be much quieter to a sound meter but changing the timbre of the sound makes the ride more comfortable.
Nice video, it was really annoying to do this to my forester and it took waaay more than I thought it would, but I hope it’ll make a difference because I haven’t driven it yet and I still have to finish putting it back together. Hopefully I’ll get some time to start making videos on the partial restoration that I’m performing on it soon! Only thing I would correct you on is to not take the clips (you call them studs) like that. That tool shouldn’t go under the clip directly. First you use the lever to pop the center of the clip out (it shouldn’t come out all the way but some do) and only then you pry underneath it. That’s how they are made to work and you risk damaging the clip or the plastic that it’s holding by just prying them out directly. Also, don’t tighten your wheels by stepping on the wrench, buy a torque wrench and use that. Thanks for doing this and showing the results!
Hey nice work! I've turned on notifications so I won't miss any updates if you add more soundproofing in future. It's interesting how car manufacturers have progressively made their cars better soundproofed over time. I'm a Toyota owner too and in the earlier stages of soundproofing it... Not the quietest cars but ripe for DIY improvement. One thing that Toyota have been doing in the factory more recently I've heard is blocking up gaps and hollows and channels where noise might enter the cabin... Might be something to consider for yourself I dunno... Any gaps in parts of the vehicle or materials that actually block sound transmission can let through an unexpected amount of noise for the size of the gap... Like when you open a car window just a tiny crack you notice a huge amount of noise gets in as though you'd opened it a lot more... Even when parked in traffic so it's not from wind or air movement it's just from the properties of sound travel... A general principal to keep in mind... And as everyone in the comments here is giving their two cents worth I might as well make another suggestion too... I've done lots of research on tyres over the years... and I'm not sure how meaningful those eu tyre label decibel ratings are... I'm sure they have some degree of accuracy but a more reliable source I think would be comparative testing that's done for example on some TH-cam channels like Tyre Reviews I think a good one is called. Unfortunately though there's not a lot of good comparative testing out there... So I'm planning on doing some of my own myself... But there are definitely tyres that are quieter than the ones you've got I would wager. And probably quieter than those Yokohama tyres too... Maybe if and when the ones you've got wear out and it's time for new ones... Because fair enough you got them for a bargain and they're decent brands and quality so not the worst either I'm sure and I'm not criticizing that decision at all... There's not enough guidance out there to make spending big money on tyres sensible... I might suggest looking at Goodyear Efficientgrip variants though. I remember they were the quietest in one big test. ...I'm planning on upgrading the wheels on my car like you did too! I hadn't heard that alloy wheels might be quieter but I have often wondered about it actually... So I learnt something! Cheers
It seems to me that noise coming from the tires is the biggest factor. I drove a Mercedes for many years and of course it was very quiet. Now I drive a Honda Fit. It is a nice little car, but very noisy at highway speeds, particularly when the pavement is rough. It is very noticeable when the road transitions from a smooth surface to a rougher one. My best bet would be to insulate around the wheel wells somehow, and/or replace the current tires with quieter ones. Also, I think it is not necessary to cover all that metal with the "kilmat" (smaller pieces would do it). The foam material seems a good solution to absorb higher frequencies, and the vinyl doesn't seem to be worth the trouble and cost. Thanks for the detailed video!
Appreciate the comprehensive guide and eloquent delivery, thank you! I've pondered doing this on a sister car... the older 107. As a wacky but half-scientific idea I'd like to compare the baseline with the (rear of the) car filled with cushions/duvets - just to see how much absorption they'd provide. Not a practical idea but interesting perhaps. Regarding matting over the wheel liners... if nothing else they provide a nice home for rodents - as I found out on my Verso - at least they chewed that and not the wiring 😂
Do NOT cut your vapor barrier like that, there's a reason for the vapor barrier, and it is to keep moisture OUTSIDE of your car. Water that rains onto your windows goes down the doors and drains through the doors. With heavy rain and a cut vapor barrier, the water will make its way inside the cabin and you will end up with a soggy floor.
Thanks dude for making this video, probably one of the most detailed I've seen so far based on your effort and patience on soundproofing your car. Just to ask, how did those mats you placed along the wheel arches and liners? did those hold and stick on after a few months tilll now? Thanks mate.
Thanks for the nice comment. Appreciate it! The mats on the plastic wheel arch liners seem to be holding up well and there is no worry of rust on the plastic parts, which is nice. I actually popped one off the other day and everything is still where it was. The mats that I put on the metal part of the wheel well have been there for about a year-ish and I do plan on getting a heat gun and replacing them/looking to see if there is any panel rust, so stick around as I'll post on the channel when I do👍
Yeah, I can certainly see that argument. I think it's important to think of the improvements outside of the decibel scale as that only measures sound pressure, which is certainly important but it doesn't cover everything. When you perceive sound on a day-to-day basis in the cabin, you do notice it and there is still a lot that can be done to lower decibels, but it's whether you think you are getting value out of it, isn't it. For me, I think it is absolutely worth it and you'll only really find out by doing it and experiencing it for yourself. I think the quickest win is changing your tyers to quieter ones (as an example, going from 70db to 68db). If you notice a difference with that, then you'll also feel it when you start soundproofing wheel arches and doors, etc.
Interesting video. I spotted a couple of things whilst you were taking wheels off & jacking up etc, so here is some unsolicited advice. First, don't remove wheel nuts completely until the car is off the ground; this is likely the reason that the last 2 were so difficult to remove. Removing a wheel nut whilst another is tight causes the wheel to not sit quite as flush, meaning there is more tension held in the remaining bolts. Usually, i'd crack the wheel nuts loose before jacking up, before removing them completely. Another thing about jack stands. Those ratcheting stands are really strong, and usually come with a pin system to secure the ratchet in place which adds more stability and another line of defence if something bad were to happen.
I've used some footage, but it's been made from the ground up, so lots of new stuff 👍 The beginning section is entirely new, the wheel arch section now actually covers removing the wheel arch, the door section covers two new materials you can use, There is an updated section for the bonnet + firewall + footwell and an entirely new section on tyres, so I'd recommend you give it a watch if you have the time.
@@jamieaygo One thing I've noticed is at 29:17. The before/after parts sound too similar. Are you sure those are actually different audio clips? Otherwise, great video. This inspires me to soundproof my Nissan Juke
Yes, you are right, they do sound similar. In honesty, I've worked on this for months so I wouldn't like to rely on my memory and give you an affirmative yes or no. I'd be more inclined to view the results in totality as a more accurate measure of improvement, but good spot!
Why are you applying sound deadening to the bonnet? Surely parts closer to your ears and attached to the cabin would be a better place to start? Doors, roof, floor? Curious…
The butyl mats are mainly to stop panel vibration, so they are still useful when applied on the bonnet. I'm working on doing the floor and roof in a separate video 👍
Theres absolutely no point in adding MLV in plastic door cards if you don't cover it 100% plus MLV is mainly used on floors with as much coverage as possible
I'm not entirely sure at present, but I will update that in the description when I get around to it. I'll also be looking at how it impacts MPG's, too.
If you put the wheel youve just taken off the car , under the car you give your self a survival space should the car fall. Costs nothing and takes very little effort , as well as it being the difference between cutting your foot off , and walking away with a bruise , it lets you get the jack back under the car should it fall ... worth a thought.
Is it just me who can barely notice the difference all this made? Im thinking about doing my '78 Cavalier but if its not going to make much difference, i might forgo it and avoid any chance of rust forming behind a poorly adhered mat
Hi there. I think it's worth noting a few things. I've only focused on sound pressure here that is measured with a decibel meter. viewers on TH-cam seem to be addicted to decibel meter results even though it's only really part of the overall picture as it's only measuring sound pressure. It doesn't include timbre (that quality of a sound), which this does improve by turning something like an annoying whine into something more enjoyable. Texture is also missed and because you are adding a new material into the mix, it changes how sound travels and interacts with each object, creating a more pleasant place to be. Vibration is also improved, so if you have an older car, it will make a nice difference to the quality of your ride and I will caveat all of the above with this: Buy quality stuff - The sound deadening mats I used are only 50mil, but most these days are 70-80mil. buying quality materials matters, so if I were to do it again, I would likely start there.
If anything it should make your sound system sound better! Some of the products I've used mention this specifically. The only thing some people have noted is that it takes away from the rattle that you get when you turn up the volume (bass specifically), but if you'd rather not have that then happy days.
Two years ago I did soundproofing in my car mainly to improve sound quality. It WILL be massively better with the same setup you have already. Road noise was just an additional bonus for me :) Treated all 4 doors and engine cover in Peugeot 3008 from 2018. Way better and nicer car for couple hundreds :)
Yeah, I can see that. It depends what you value it for. For me, I like that it makes my rides around town and on the motorway quieter, but you are right in that it could potentially impact things like fuel economy, which is what some people value about these cars.
I'd say adding all that soundproofing to a cheap car like that makes the most sense. An expensive car is likely to be much better soundproofed to begin with, which results in diminishing returns. Secondly, expensive cars come with more in terms of equipment and overall complexity adding to potential damage if mistakes are made in the soundproofing process. The cost of future repairs made for any reason may be increased more when adding soundproofing to a more expensive car as the soundproofing may have to be removed and put back on in some cases. The most bang for buck is in getting the smallest possible rims and tires with the tallest walls as possible with the lowest noise rating possible. As for the car itself, the wheel walls are where most of the action is because tire noise dominates the overall noise profile upwards from a relatively low speed. The boot, the floor and the footwell are most likely the next easiest parts. In a video by The Car Car Nut, he removed the dashboard of a Lexus RX, which revealed the firewall. It was covered with soundproofing material almost entirely, which partly explains why that SUV is so quiet. th-cam.com/video/PI5YskUPEyg/w-d-xo.html
😱I Overspent! This Will Stop You - subscribepage.io/8SqMmc
As someone who works in the noise field, it's worth noting that a 1-2 dB noise difference isn't really noticeable in the human ear, 3dB difference is slightly noticeable, 5dB is a distinct difference, 10 dB difference is a doubling/ halving in noise. Definitely invest in a breaker bar for your wheel nuts, and a jack!
Thanks, dann.
@@ingsterschmingster5768 3db is the doubling of power. 10db is the apparent doubling of volume. Human hearing is logarithmic.
How can it be, that he soundproofed so much, and in the result its only about 2dB quieter? I would say 50-60 hours of work, and probably about 1,5k£ wasn't worth to get that kind of low results.
I mean im after few videos with soundproofing car, and many of other cars get 2x more from just silencing doors OR wheel arch (not both at the same time).
The first thing that comes to mind immediately is that, the @jamieaygo made something terrible wrong, or other videos are manipulated.
@dann6341 can you tell which one is it?
And sorry for poor english, not my native :)
How can it be, that he soundproofed so much, and in the result its only about 2dB quieter? I would say 50-60 hours of work, and probably about 1,5k£ wasn't worth to get that kind of low results.
I mean im after few videos with soundproofing car, and many of other cars get 2x more from just silencing doors OR wheel arch (not both at the same time).
The first thing that comes to mind immediately is that, the @jamieaygo made something terrible wrong, or other videos are manipulated.
@dann6341 can you tell which one is it?
Also sorry for poor english, not my native :)
Finally a hands on attitude for untrained but interested ppl. And you show what you do for ex the sound deadning in the wheel section. Everbody else talks about it, but nobody showed it. thanks for that, helps me a lot seeing it visually.
A little side note: I would emphasize the three layers clearer to your audience, because I had to rewind a few time to get the layers right as a beginner with the project of sound deadning.
Thank you! Yeah, that’s a good idea. It actually took me a few times to get it to sink in, too 😂
When you remove the wheelwell clips, you pull the center out first, and that will make removing the clip easier.
Cheers for the tip, mate!
Safety: as well as using axle stands, chock the wheel on the opposite corner both front and back of the tyre. Especially when working on a slippery, loose, or sloped surface! A pair of folding wheel chocks is cheap, or if you have scrap wood around you can make your own.
A lot of sound deadening is reducing the pitch of the noise - that's what adding mass to a vibrating panel does. Low pitched rumbles are less annoying than whistles and hissing noises. It may not be much quieter to a sound meter but changing the timbre of the sound makes the ride more comfortable.
Thanks for adding to this so thoughtfully, Greg.
Nice video, it was really annoying to do this to my forester and it took waaay more than I thought it would, but I hope it’ll make a difference because I haven’t driven it yet and I still have to finish putting it back together. Hopefully I’ll get some time to start making videos on the partial restoration that I’m performing on it soon!
Only thing I would correct you on is to not take the clips (you call them studs) like that. That tool shouldn’t go under the clip directly. First you use the lever to pop the center of the clip out (it shouldn’t come out all the way but some do) and only then you pry underneath it. That’s how they are made to work and you risk damaging the clip or the plastic that it’s holding by just prying them out directly. Also, don’t tighten your wheels by stepping on the wrench, buy a torque wrench and use that.
Thanks for doing this and showing the results!
Nice! Love the Forester. Such an underrated car! Thanks for the tip on the clips. Will keep an eye out going forward.
Hey nice work! I've turned on notifications so I won't miss any updates if you add more soundproofing in future. It's interesting how car manufacturers have progressively made their cars better soundproofed over time. I'm a Toyota owner too and in the earlier stages of soundproofing it... Not the quietest cars but ripe for DIY improvement. One thing that Toyota have been doing in the factory more recently I've heard is blocking up gaps and hollows and channels where noise might enter the cabin... Might be something to consider for yourself I dunno... Any gaps in parts of the vehicle or materials that actually block sound transmission can let through an unexpected amount of noise for the size of the gap... Like when you open a car window just a tiny crack you notice a huge amount of noise gets in as though you'd opened it a lot more... Even when parked in traffic so it's not from wind or air movement it's just from the properties of sound travel... A general principal to keep in mind... And as everyone in the comments here is giving their two cents worth I might as well make another suggestion too... I've done lots of research on tyres over the years... and I'm not sure how meaningful those eu tyre label decibel ratings are... I'm sure they have some degree of accuracy but a more reliable source I think would be comparative testing that's done for example on some TH-cam channels like Tyre Reviews I think a good one is called. Unfortunately though there's not a lot of good comparative testing out there... So I'm planning on doing some of my own myself... But there are definitely tyres that are quieter than the ones you've got I would wager. And probably quieter than those Yokohama tyres too... Maybe if and when the ones you've got wear out and it's time for new ones... Because fair enough you got them for a bargain and they're decent brands and quality so not the worst either I'm sure and I'm not criticizing that decision at all... There's not enough guidance out there to make spending big money on tyres sensible... I might suggest looking at Goodyear Efficientgrip variants though. I remember they were the quietest in one big test. ...I'm planning on upgrading the wheels on my car like you did too! I hadn't heard that alloy wheels might be quieter but I have often wondered about it actually... So I learnt something! Cheers
Thanks for adding to the conversation in such a meaningful way. Sure to help others!
It seems to me that noise coming from the tires is the biggest factor. I drove a Mercedes for many years and of course it was very quiet. Now I drive a Honda Fit. It is a nice little car, but very noisy at highway speeds, particularly when the pavement is rough. It is very noticeable when the road transitions from a smooth surface to a rougher one. My best bet would be to insulate around the wheel wells somehow, and/or replace the current tires with quieter ones.
Also, I think it is not necessary to cover all that metal with the "kilmat" (smaller pieces would do it). The foam material seems a good solution to absorb higher frequencies, and the vinyl doesn't seem to be worth the trouble and cost. Thanks for the detailed video!
I think you're spot on with what you could do to the Honda and thanks for the tips!
Appreciate the comprehensive guide and eloquent delivery, thank you! I've pondered doing this on a sister car... the older 107. As a wacky but half-scientific idea I'd like to compare the baseline with the (rear of the) car filled with cushions/duvets - just to see how much absorption they'd provide. Not a practical idea but interesting perhaps. Regarding matting over the wheel liners... if nothing else they provide a nice home for rodents - as I found out on my Verso - at least they chewed that and not the wiring 😂
I love these types of ideas!!
Do NOT cut your vapor barrier like that, there's a reason for the vapor barrier, and it is to keep moisture OUTSIDE of your car. Water that rains onto your windows goes down the doors and drains through the doors. With heavy rain and a cut vapor barrier, the water will make its way inside the cabin and you will end up with a soggy floor.
Thank you! One to know for next time time.
Thanks dude for making this video, probably one of the most detailed I've seen so far based on your effort and patience on soundproofing your car. Just to ask, how did those mats you placed along the wheel arches and liners? did those hold and stick on after a few months tilll now? Thanks mate.
Thanks for the nice comment. Appreciate it! The mats on the plastic wheel arch liners seem to be holding up well and there is no worry of rust on the plastic parts, which is nice. I actually popped one off the other day and everything is still where it was. The mats that I put on the metal part of the wheel well have been there for about a year-ish and I do plan on getting a heat gun and replacing them/looking to see if there is any panel rust, so stick around as I'll post on the channel when I do👍
@@jamieaygo its more effective to just use undercoating spray at that point for the exposed metal parts of the wheel arches
Great series, saw every one of them.
Too kind!
Seems like a significant amount of effort for 1-2 decibel drops!
Yeah, I can certainly see that argument. I think it's important to think of the improvements outside of the decibel scale as that only measures sound pressure, which is certainly important but it doesn't cover everything. When you perceive sound on a day-to-day basis in the cabin, you do notice it and there is still a lot that can be done to lower decibels, but it's whether you think you are getting value out of it, isn't it. For me, I think it is absolutely worth it and you'll only really find out by doing it and experiencing it for yourself. I think the quickest win is changing your tyers to quieter ones (as an example, going from 70db to 68db). If you notice a difference with that, then you'll also feel it when you start soundproofing wheel arches and doors, etc.
Another interesting and informative video review. Thanks 🎉
Thank you!
Interesting video. I spotted a couple of things whilst you were taking wheels off & jacking up etc, so here is some unsolicited advice. First, don't remove wheel nuts completely until the car is off the ground; this is likely the reason that the last 2 were so difficult to remove. Removing a wheel nut whilst another is tight causes the wheel to not sit quite as flush, meaning there is more tension held in the remaining bolts. Usually, i'd crack the wheel nuts loose before jacking up, before removing them completely.
Another thing about jack stands. Those ratcheting stands are really strong, and usually come with a pin system to secure the ratchet in place which adds more stability and another line of defence if something bad were to happen.
Cheers, Jake! Appreciate the advice!
Thanks! Really helpful!
Glad it helped!
Is this a compilation of all previous videos you've done?
I've used some footage, but it's been made from the ground up, so lots of new stuff 👍 The beginning section is entirely new, the wheel arch section now actually covers removing the wheel arch, the door section covers two new materials you can use, There is an updated section for the bonnet + firewall + footwell and an entirely new section on tyres, so I'd recommend you give it a watch if you have the time.
@@jamieaygo One thing I've noticed is at 29:17. The before/after parts sound too similar. Are you sure those are actually different audio clips?
Otherwise, great video. This inspires me to soundproof my Nissan Juke
Yes, you are right, they do sound similar. In honesty, I've worked on this for months so I wouldn't like to rely on my memory and give you an affirmative yes or no. I'd be more inclined to view the results in totality as a more accurate measure of improvement, but good spot!
My Aygo is the quietest car I've owned, having said that I've still found your videos interesting.
That's awesome to hear! Thank you!
@@jamieaygo Blimey somebody put those wheel bolts in way way too tight!
Yeah, they were almost welded on!
Why are you applying sound deadening to the bonnet? Surely parts closer to your ears and attached to the cabin would be a better place to start? Doors, roof, floor? Curious…
The butyl mats are mainly to stop panel vibration, so they are still useful when applied on the bonnet. I'm working on doing the floor and roof in a separate video 👍
Low profile tires have a higher sound level and are rougher riding.
The taller the tire wall the less noise as there is more rubber to absorb vibration.
Theres absolutely no point in adding MLV in plastic door cards if you don't cover it 100% plus MLV is mainly used on floors with as much coverage as possible
How much weight did it add
I'm not entirely sure at present, but I will update that in the description when I get around to it. I'll also be looking at how it impacts MPG's, too.
If you put the wheel youve just taken off the car , under the car you give your self a survival space should the car fall. Costs nothing and takes very little effort , as well as it being the difference between cutting your foot off , and walking away with a bruise , it lets you get the jack back under the car should it fall ... worth a thought.
Great tip that, Tom. Thanks for sharing!
Aygo's are not really loud cars from standard.
Is it just me who can barely notice the difference all this made? Im thinking about doing my '78 Cavalier but if its not going to make much difference, i might forgo it and avoid any chance of rust forming behind a poorly adhered mat
Hi there. I think it's worth noting a few things. I've only focused on sound pressure here that is measured with a decibel meter. viewers on TH-cam seem to be addicted to decibel meter results even though it's only really part of the overall picture as it's only measuring sound pressure. It doesn't include timbre (that quality of a sound), which this does improve by turning something like an annoying whine into something more enjoyable. Texture is also missed and because you are adding a new material into the mix, it changes how sound travels and interacts with each object, creating a more pleasant place to be. Vibration is also improved, so if you have an older car, it will make a nice difference to the quality of your ride and I will caveat all of the above with this: Buy quality stuff - The sound deadening mats I used are only 50mil, but most these days are 70-80mil. buying quality materials matters, so if I were to do it again, I would likely start there.
shoud've change scale in dBA, no dBb, difference will be 3-5 dB min
Ah, interesting. Will look into this, thanks!
electric knife is needed to cut foam
Thanks for the tip, Will! I'll look at picking one up!
Or a bread knife isn't bad either. The serrations help make a cleaner cut than a single sharpened blade
how will this affect my sound system. Does it lower the volume from the speakers?
If anything it should make your sound system sound better! Some of the products I've used mention this specifically. The only thing some people have noted is that it takes away from the rattle that you get when you turn up the volume (bass specifically), but if you'd rather not have that then happy days.
Two years ago I did soundproofing in my car mainly to improve sound quality. It WILL be massively better with the same setup you have already.
Road noise was just an additional bonus for me :)
Treated all 4 doors and engine cover in Peugeot 3008 from 2018. Way better and nicer car for couple hundreds :)
Applying all those soundproofing measures for cars of that class doesn't make a lot of sense
Yeah, I can see that. It depends what you value it for. For me, I like that it makes my rides around town and on the motorway quieter, but you are right in that it could potentially impact things like fuel economy, which is what some people value about these cars.
I'd say adding all that soundproofing to a cheap car like that makes the most sense. An expensive car is likely to be much better soundproofed to begin with, which results in diminishing returns. Secondly, expensive cars come with more in terms of equipment and overall complexity adding to potential damage if mistakes are made in the soundproofing process. The cost of future repairs made for any reason may be increased more when adding soundproofing to a more expensive car as the soundproofing may have to be removed and put back on in some cases.
The most bang for buck is in getting the smallest possible rims and tires with the tallest walls as possible with the lowest noise rating possible. As for the car itself, the wheel walls are where most of the action is because tire noise dominates the overall noise profile upwards from a relatively low speed. The boot, the floor and the footwell are most likely the next easiest parts.
In a video by The Car Car Nut, he removed the dashboard of a Lexus RX, which revealed the firewall. It was covered with soundproofing material almost entirely, which partly explains why that SUV is so quiet.
th-cam.com/video/PI5YskUPEyg/w-d-xo.html