I had 4 12" Rockford Power HX2's in my Ford Ranger ext. cab on 2 JBL 1200 watt mono amps with 2 batcaps, I think 4 million farads of capacitorocity, and 0 guage wire runnin from the front...nice lookin wire I got off ebay. I had to make my own box, and porting out 2.5 ft3 per sub, it took up everything behind the seats, had to remove rear folding seats, and seats were actually a little too forwarded for comfort. I had to put 2 4" pvc ports aiming out the top of each chamber, and had amps mounted on top, only thing I regret was my lousy carpet job on the box, aside from the window shaking out like 1" (literally), it was pretty bad...