well I just bought a new 2005 Acura and from previous experiences decided to try something new.. I took out the carpeting, etc and I got liquidnail (epoxy) and filled most of the cracks with that, and then I took my vehicle to a truck bed liner place, and had my trunk sprayed with 'Rhino-Liner' to stiffen up and seal most of it, then I bought 30 cubic feet of dynamat and some extra adhesive to aid in keeping it glued on, I have a pretty loud system, and it does NOT rattle, period. As far as dampining goes, it works pretty well as noiseproofing //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif Keeps old people happier I suppose. another thing is the more space your 'box' occupies the less resonating your bass is going to do, best bet is to not use boxes and intergrate your system into your vehicle opposed to having all of that stuff concentrated into a single area. I have 4 Kenwood 1600/1 mono Excelon amplifiers and 4 alpine type R subs along with a kenwood 800/4 amp for highs / mids. a buddy an I cut into the floors and dropped pans where the amps fit into, ran the wires through the vehicles interior, under carpet/trim/roof, whatever was the shortest path.. worked quite nicely.. and the trunk if you wern't looking doesn't have any visible objects in it, so it's just like a 'bass chamber' I suppose you could say. But yea, the more you keep out of the way and the better you tighten everything up and seal reduces rattle and allows for more bass resonation and with all of the liner in your trunk it's just going to go forward instead of dissipating, so yeah.. It works to spend a little extra. //content.invisioncic.com/y282845/emoticons/bowdown.gif.b85b23b82970bd22fb6b549c3392f016.gif
ps, the cut's are to dimension and radius--we used silicone to seal them