There was a thread that I had seen of some one using a spray on or roll on sound dampening in their trunk. I can't seem to find it?

What was this stuff and how did the person who used it like it?

I want something that will be easier to install than say Dynomat and that will get into the nooks and crannies of the trunk area.

I'm looking to do all 4 doors, the rear seat, rear deck, and trunk. The trunk and rear deck are my primary concerns right now as I'm preparing to install my amps and sub soon. I can do the rest later.