No room behind the seat covering near the bass speaker at all. PERIOD. Not for anything bigger than a iPod.

There is plenty of room under the front floor, forward of the stereo amplifier, but you'd have an awful time changing discs.

I placed mine in the boot (cargo area) under the floor cover on the passenger side. There is already a pocket in the styrofoam for a first aid kit and I just made it deeper.

If you really don't want it there, you MAY be able to mount it behind the passenger seat, but you will never be able to get the seat all the way back again.

Good luck with finding your ideal location.

Cheers!