sorry, i'm totally lost on that last paragraph there
so i have a perfectly rectangular box... what I plan to do is cut out a piece of mdf roughly the size of the back and using some sort of wood boards, make triangles that will mount on the back of the sub box, then the mdf the size of the back will mount on those... this will give the appearance of a box with a slanted back (as close to the angle of the back seats as possible), but there will be a gap with an open bottom to hide the wires in. Then the amps will be mounted to the angled section on the back there with a sheet of plexi suspended with standoffs about an inch above the amps. Then i'll put a couple fans on each side of the plexi to get air flowing underneath it...
does that make any sense?