dynamat, hushmat,noize control, all work pretty well. Especially on floors...they won't rot out again. Also lizard skin spray on works well, it can get into lots of places. Line x bedliner works great, will seal pinholes in the floor, makes for a ridgid panel that will never rot. spray on top and bottom of floor to get max. protection. the silver lined sound deadening pad they sell at the car shows works very well also. For a cheaper alternative, use 8 lb carpet pad. I used this in my truck along with hushmat, wow, what a difference. I just finished building a 50 where I used 2 bulk packs + of dynamat, the silver padding stuff on EVERY surface inside and it sounds about like the customer's mercedes.
