Anyone have a powered sub enclosure behind the seat?

[pat]

I was looking at crutchfield and this looked like a good deal for the price. Does it matter that it will be behind the seat facing one side of the cab or the other, as opposed to sitting in the trunk of a car? I dont need a ton of bass, just a decent thump. I was wondering how this would work compared to a couple 8"s or 10"s in boxes facing the seat. It may be my best option considering how little room I have.
http://www.crutchfield.com/S-Ms6X0kQ...TB10AT&g=51000