What you're trying to do is cover the majority of the tub w/sound deadening material. Whether that be butyl or a foam product is up to you. I liked the butyl myself. In my case I did the entire interior of the car up to the base of the windows starting from the front passenger foot wells (on the inside of the car) and extending all the way back into the trunk. I probably used about 130 sq ft of material. The goal is to cover the entire area w/material. Leave no gaps.
For the front wheel wells (exterior) take the tires off; then the plastic wheel wells and cover the exterior of the drivers & passengers tub starting from the top to the bottom with butyl. When handling butyl I recommend cutting it in strips. I typically would cut mine about 4" width and the length of the roll it came in. Then roll it down with the tool they provide or go get a roller from a hardware store if they didn't. The combination of covering the exterior wheel wells and the entire interior all the way back to and including the rear seats does a good job of cutting down the majority of exterior noise.
For the rear wheel wells cover the entire trunk area and work your way up the wheel wells. Cover all exposed areas and do the same for the rear quarters and top of the trunk. To really knock noise add a layer of 5mm or 10mm self-stick foam (black closed cell). The 5mm is easier to work with.
The only area I haven't done is the ceiling. I know I should do it but I just haven't gotten around to it yet and I'm somewhat concerned with summer heat and long term material stability.
One more thing... buy decent butyl; the stuff I bought was 70 - 80 mil with aluminum on one side. Maybe difficult to work with but worth the results/money.
This is the stuff I used:
https://www.ebay.com/itm/3916858600...99hNY-f:sc:ShippingMethodStandard!44130!US!-1
This stuff looks pretty good too:
https://www.ebay.com/itm/295341455282?_trkparms=amclksrc=ITM&aid=1110006&algo=HOMESPLICE.SIM&ao=1&asc=244238&meid=0f29444aa56140f59a01309b46b25905&pid=101506&rk=7&rkt=25&sd=392148429978&itm=295341455282&pmt=1&noa=0&pg=2047675&algv=SimplAMLv9PairwiseWebMskuAspectsV202110NoVariantSeedNoPLX&_trksid=p2047675.c101506.m1851&amdata=cksum:2953414552820f29444aa56140f59a01309b46b25905|enc:AQAHAAABEAzdIKOcP6rVYsexH8mCu6bA2DY6ElM67JKComxjxAnyT9vOhsWu88eBePRdeUyezF0KDA7BEV0Wzxi5ZF4sTWisrWj5kCO3n2JuWsGGoTYlq1NSJbl3hP5e%2FtxqpAqLGN32NMTLUfsp46PM0o2l244cwIT00iAgkBfGwJ89VCezhX%2FagNR2mHOy8KbTs3YvD3UGi4ta6W78PV415tsrwWCo2gFzW9KN6ZBzpLFmrvIdhD%2F1x2aJ%2BOkcpR0xnZejDbABinP%2BeUhHXzKaYGGkMuj0nJ98wQ%2BcYKInuqwrqJ6NqDAnPbcZA%2FKJ8lt5KMx2Y0hNV%2F3bh3RGafHYZtjp2Iqu1ujnOtl2H857vLGcRpJ%2F|ampidL_CLK|clp:2047675
I will tell you this. Would I do it again if I had to? Hell yes!!!
Thanks a lot. I started to use some strips according to the AcoustiShield plan above in this thread.
Need to buy some more and will buy some heavy material. I have some old stuff from HiFi equipment with 0.3 mm aluminium from my younger days
If you get older, you need a quiet car .... And I guess a good chiropractic after crawling inside the trunk.