[J-Spec C10]

I realize that I came in the middle of what apears to be a large discussion, but thought I'd throw in my testimonial to the low cost brownbread sound deadening since it relates to this thread.
I used it in my truck. I cut and applied in 4" squares in a checkeboard pattern wherever possible. It greatly reduced the exterior noises inside the cab. The idea behind the checkerboard is that you really only have to "deaden" the peaks and valleys of the panel's vibration curve which makes it flat. This leaves the whole panel evectively deadened for 1/2 of the price.

Hope I save you some $$ with this tip.