The kicker flat subs are pretty good. My brother and I put a pair of 10's under rear seat of F-150, and they sounded great. They are pretty cheap as well.
i actually was thinking and i could just put a 1 inch space between the box and the sub and add an inch to the depth so thats not an issue...
im looking for some subs around 300-500 RMS at $100-150 a piece
im looking for some subs that really bump and hit the lows really well...i want it to hit me in the chest when i play Put On by Jeezy...not my butt like my subs are doing now, it doesnt really vibrate too much, i want a full body massage haha