Dynamat / Peal n Seal... yes or no

Is Dynamat heavy? If I were to install it in the doors, under the carpet, quarters, trunk, roof - how much weight are we talking? I put some under the rug in my Charger and if memory serves, it's a foil-backed tar-type material that's pretty dense and heavy.

Also, if I were to stick the stuff on the inside roof - above the headliner, do you think I'd have adhesion issues with the hot sun beating on the roof of the car?