oh yes there certainly are, dynomat is just one of the big name one's that everyone uses, you can use pretty much anything, i used some 3D seeler spray crap, that worked, for (2) 10' xplods, lol,

 

Dynomat just weighs sooooo damn much. Personally I say just dampen whatever is rattling which is probably the spoiler and maybe license plate.

 

ya it does waigh alot, but if your putting a big system in it really doesnt matter in the end, also the sheet metal on the bottom of my hatch rattled, with no spoiler, and that was with my xplod's

 

I did my trunk when I put my subs in and it helped with the sound quality a lot. I did the underside of the trunklid, and the rear around the back of the taillighs and such. My buddy used to work at best buy so i got the big box of it for like half price.

 

Niiiiiiice.....i got mine at cost....but sounds like you got a waaaaay better deal [8D] that was a lucky find congrats!

 

The reason you do the floor of the car it mainly to eliminate road noise. you can use the spray stuff in the wheel wells and get rid of most of the noise with just that.

-Marc