Actually - that was in my original plan - to have a cover that sets on top (matching CF vinyl) designed for airflow/convection, etc. However, I discovered that I *rarely* use the back end if ever to carry stuff. If I do need to put anything in the back, I usually just recline the back seats backwards and slide the bags/goods onto the seats. I don't know, works for me...
I fab'ed the two tier rack (bottom hides wiring, top displays amps) so that it's bolted down by all four holes in the rear floor. Two bolts are under the amps, which in turn are secured by special hardware screws (not easy to remove for the goblins out there...). The lid then props up on a hinge to expose the other two bolts towards the rear end.
Over all it's pretty clean and secure.
0 & 4 gauge power/ground wires.... Brushed steel bottom covered by plexi which is what the amps rest on....
The stitching was only $120 done by DMUD (dmud.com) here in Denver.
-biju.