[JLMounce]

Those products do the same thing. With the under carpet lite there is an adhesive spray that you want to get if you go that route.

[DM3]

So I purchased Noico 80 mil car sound deadening mat, below is a picture next to a piece of Dynamat Extreme, same thickness, will install a few sections this weekend.

Also below is the Noico Green 170 mil car waterproof sound insulation will be installing on the roof of the car, but may now wait until the body work is finished due to the excessive dust that will be generated.

[TAKerry]

Will add my experience with my '77. I built my car as close to factory as possible. I used the factory type sound deadener, which is akin to VERY heavy tar paper, about 1/8" thick or so. I did use the Dynamat xtreme on the trunk divider and the rear wheel wells. My car is LOUD inside. On the car I am building now I plan on using the dense foam product.

[LeighP]

Not a huge fan of using a heavy product on the inner roof.....I've seen them decouple from heat and gravity.
I had a good result using a light insulation made of thin alloy foil sandwiching air filled bubble insulation.....its light, forms easily and I glued it on with spray adhesive.