I am in the process of installing the stuff from Home Depot in my car. I feel that the $20 I have invested is enough. It is cheap enough that I can even double or triple it up if I need to. I didn't find anything that had adhesive or aluminum on it though.
The way I tested my car was to turn on the eMpeg and see how much sound is escaping from certain places around my car. The door panels and trunk were pretty bad. Even at -35db on the player I can hear the music a little bit. My Saturn has pretty much no soundproofing material in it now. Hopefully, after putting this stuff in, and covering the inside of the wheel wells, the music will stay in and the raod noise will stay out more than is happening now.