I doubled the application in the trunk and don't think it did a thing. I ended up welding in a balance tube for the exhaust which did way more the any sound deadening. I now have a loud exhaust but it doesn't vibrate the interior. Now at 70mph I can carry on a normal conversation. Infact the car is louder inside at 60mph then any other speed. Hey Distant if you make it to the Dyno tune in NJ I'll drive you around and we can compare notes on exhaust noise.