I used Dynamat Extreme in my GTX project (attached), and I will tell you that is sticks and will not come up...I also bought Dynamat Superlight as well, but it would end up taking two layers to equal the Extreme, but would be slightly thicker with two layers.

I am going to buy another box of extreme to do under the rear seat area. I am very impressed with the sound deadening.

I will use the lightweight for my '32 ford, and just double-up in some areas. Also, Dynamat is manufactured here in Cincinnati, and I have compared other products, and I ended up buying dynamat because of quality.

just my 2 cents.

BR, Mark