I have removed all the foam filler and lined it with dynomat. I bought a piece of 4x4 half inch plywood and made a custom enclosed box. I put in two 10 inch punch stage 1's on each side (fit perfectly) and mounted an amp in the middle, then carpeted it. Its sweet. I was also able to stuff the small tire air compressor up behind the rear bumper on the drivers side...there's just enough room. There are a few pics in my gallery of the process. I also raised up the OEM floor piece that was there by cutting a 2x4 in 2 inch pieces and mounted them vertically in the corners with velcro on top of them. The old floor now rests, or hovers, 2 inches above the subwoofers to make the whole set-up invisible. Nobody knows they are even there and they sound nice.

I'm not worried that the foam is not there anymore...when my times up, its up. At least I was having fun in my Crossfire. You only are on this planet once! Just my 2 cents.