I have my two amps in the spare wheel well myself. Was just curious on how you did it. I should take pictures sometime of mine. Although, my wires are a mess. When I installed it I had intentions to go back and clean it up. 3 years later, still haven't cleaned up the wires. lol.
What I did was made a wooden box (without a top) to mount the amps in. I was worried about heat, so I installed two fans, one pulling air in, one pushing air out to keep it nice and cool. I have never had an issue with heat. The floor of the box has a hole in the center and goes right over the spare wheel. I can remove everything in about 5 minutes to get to the spare.