Chris

I built my own sealed box and put a 12" under the rear driver's side seat of my supercrew. I put the amp under the other seat. Sounds great.

01f1502wd

I had a MTX 10" under my passenger rear seat, but couldnt fold down the seat. So now I have a box with 2 10"s from supercrewsound.com thats behind the backseat, works good.

DSG

Update:

Almost got the box built, subs have been ordered. I chose to go with Sundown Audio E8v3. they are some beefy subs, and according to the reviews on amazon hit better than some 10's and 12's. in order to make this box work, i will be raising the entire rear seat up 3 inches. it will look a little goofy. but i got a rough mock up done and it's actually not that bad, pic to come.