http://www.dynamat.com/
I have a 1969 Camaro With 2 10's in the trunk, 2 6x9s in the rear, and 3x5s in the kick panel. Let me tell you this thing is loud, as in break my rear view mirror loud. As with almost all old muscle cars most of the body is metal so vibration was a huge worry throughout this project. We used dynamat throughout the entire vehicle and let me tell you there is almost no vibration. All the big name builders use it for a reason. Def worth all the money!