Does anyone have a write up or pics of how to mount an amp to the rear seat? Some people have said to put a piece of MDF behind the carpet but will that be enough to hold it? Also will the carpet just go over the MDF and wont it leave a bulge?

 

I would do this:
Cut the proper size MDF, wrap it in matching carpet, nail it dow, then nail the amp into that. Feed the wires through the bottom so the carpet covers it up and your golden.

 

Self tapping screws will allow you to mount the amp directly to any part of the seat frame and cross-structure.