Before selling my 94 Firebird, the entire inside of the car was lined with Dynamat and Tsunami Mat sound deadener stuff. The car was quiet--worth it's weight in gold, or so I thought. Had some left over Tsunami stuff and packed it away with our household goods. It was stored, in its original box for about 3.5 years. Found it when unpacking one of the boxes with my tools last month and set it aside to use when lining the doors of the Civic. Opened the box today and the stuff crumbled in my hands--it was all dried up. Holy Cow! and it covers about half the Firebird interior. This is bad. What it looks like is that pretty soon, the stuff is going to start crumbling and falling off of inside door panels and other places that it was stuck too. Since it formed better than Dynamat, used it to line speaker enclosures and other speaker areas, particularly the plastic rear speaker mounts in the trunk.

Seeing what happens to the stuff over time, it can't be recommmended for use in a car, and I won't ever buy it again. I feel sorry for the guy that bought my 'bird, becuz he is going to have to deal with it. At least he won't have to fight with it to pull it off the panels, becuz it has probably already done that for him. I don't know how Dynamat works under similar situations, but have lined two computers with it and one of them was done 9 years ago. The computer is still running and the Dynamat is still stuck to the inside--no crumbling or pulling away from the steel case.

Beware, don't buy Tsunami Mat.