I have a '92 240SX SE Fastback, and am getting pretty sick of the incessent rear rattle induced by my dual JL Audio 10W3's.It's almost impossible to pinpoint, since it's of course only prominent when the hatch is closed. The whole rear of the car seems to rattle, but the majority of it comes from the hatch itself I think. It's pretty cramped in there, what with the high brake light and all, and I'm wondering if Dynamat would even help.Has anyone else run into this in similar car models, and done something about it? I'd be happy to run down to the store and buy some foam to stuff in somewhere, or glue or tape or something, if I only knew where and if it would produce a clean enough sound to be worth it.I think Dynamat is too much time and money to put into my car, but if you think that's the only way to go about it, and it's surefire, tell me and I'll look into it.Thanks! =)

Sound insulation... I used Ice&Water Gard, a roofing material, which cost me about $80 to do 200 sq. feet of it in the truck. Dynamat and the others rip you off, and if you can find this stuff (check building contractors), you will save yourself a small fortune. That Great Stuff foam (expanding foam - used for sealing pipes, etc.) also works well for filling in areas that are difficult to reach or stick mats to.

I used a product called FatMat to do the entire interior of my car, 100square feet was only $130. I can definetly say that it helped reduce road, exhaust, and any other noises. Dynamat Extreme is king if you have the money. I had a friend put it in his doors and floorpan and an ambulance went by without me hearing it. I'd say set a $200 ceiling and either get a ton of FatMat and double it up, and see what happens, or get 36 square feet of Dynamat Extreme and just do the trunk and hatch area to eliminate the rattling.