Good point. I deadened my Expedition and the sound improvement was dramatic. I used Brown Bread Extreme, at bit cheaper than dynamat. And yes, it is a pain as a DIY project - but big return on the investment.

Panny 3000 PJ, 118" Carada, Denon 3300, PS3, Axiom QS8, PSB 5T, B&W sub, levitating speaker wire