Camshaft

A few months ago, I saw an audio shop site that had rebuilt the rear deck of an SC300 with MDF and attached two JL 10W3's and boxes to the bottom, fitting above the gas tank. Anyone tried this or have links to the site? I want subs to hit into the cab, so i will be doing alot of dynamating. By the way, on ebay a bulk pack of Dynamat extreme is around 130 total for 36 sq. ft, how much will I need to do the trunk, back seat, and partial floor board?