well i was going to just bolt a couple of 2x4s down and lay a sheet of MDF over them , but it turns out my trunk floor is fairly uneven, so I cant just lay down 2x4s. Here is the piece that will be hinged so I can access my spare tire:

the area behind it is where the sub box is going, Im not sure if I should do fiberglass or try MDF, its a 12" XXX, my dilemna, and where the designing needs to come in, is I have that area there, its like 32"x10"x13" (width x depth x height) and it needs to house a 12" XXX, a Kicker kx 1200.1, and a JL 300/4.

Im thinking I can fiberglass the left corner of that area for the sub, and then build a little cabinet with shelves( or amp rack) for the amps. Sort of like making a subwoofer box, and putting a shelf in it. Maybe making the front cover plexiglass.

anyways, if you have any ideas, please shoot

heres another pic