Originally Posted by JARblue

Although it sounds like you already ordered some.

And to be clear... Dynamat and similar butyl (or asphalt ) products are designed to reduce vibrations more than decibels. They are heavy and are not intended for full coverage as I have learned - sporadic application in key areas is all that should be needed. If you're looking to noticeably reduce decibel levels, you will need closed cell foam. It also weighs a lot less than dynamat, so you aren't adding 75 lbs of the stuff to your car's weight