I have 06 SD Crew and didnt want to change my deck because truck is parked outside(wont fit in garage) So I went this way.
Stock deck so looks like nothing to steal and uses steering wheel controls.
Added Eclipse 5 channel amp under rear seat after removing crappy metal flooring thingy.
Bought JL Audio Stealth 10w3 40/20/40 seat box. Works great,doesnt thump my a-- as much as I thought it would but is terrible to sit on. (what do I care I am always driving anyway)
Then ordered from Crutchfield this: http://www.crutchfield.com/App/Product/Item/Main.aspx?g=305250&i=469FRD4POD&tp=120
It works great then order a nice mount form these guys: www.mountguys.com