Help with subwoofer box?

I'm pretty sure that I'm getting a Boston Acoustics sound system from crutchfield for christmas. This is the system here...

http://www.crutchfield.com/p_700PWRPACK/Boston-Acoustics-Power-Pack-Car-Audio-System.html?tp=118

Thing is, it comes with a 12 inch sub. I'm having trouble finding a box to put in my access cab that will still allow me to use both back seats. Would it be better just to give up use of one seat and put a box back there, or is there something I could install under one of the back seats?

Any help is appreciated. Thanks.

 

Mounting depth of 5" means you should be able to fit a box behind the seat. You just won't be able to get the right air space inside if you do.

 

i have not found any boxes that are well designed for a 12" sub, that fit in the access cab keeping both rear seats. also most boxes ive seen do not have enough airspace for the 12" sub.

im in the process of building my access cab box that will be for my 12" infinity reference 1252w. its coming along, but i did not want to give up and functions that i already have in the truck, including...

full range of front seat motion
use of both rear seats
use of under storage of the rear seats
and to give me the required airspace needed for my sub (1.25cb/f)

when i get it built i will be posting pictures.