Where and how would you apply the sound-proofing? My 2008 Coupe Limited is quiet except for tire noise on the studded tire damaged Freeways. Of course mine is all stock under the hood except for K & N air filters.

I used sound-proofing generously on a 22.5 foot boat with only a Mercruiser 4.3 Chevy V 6 in it and got little return for my investment and labor. Much of it even had a clay barrier.

Jim