Full belly pan is installed!
This one took a couple of hours and cost me thirty bucks (twenty bucks for the 3x3 aluminum), but in the long run it may pay for itself. Test run was great, no melting, overheating, no smoke, cabin heat, anything like that. The coroplast is rock solid, and I used aluminum over the cat and it's not discolored after half an hour on the road.
I mounted a steel bracket for the first sheet at the back (which I had laying around) and the second sheet mounted to a bracket behind the cat, and the sheet of aluminum over the cat screwed into the front bracket already in place for the front aero panel.
The entire car has a smooth underbody now, I'll see how it fares, and what kind of affect it has on mileage.
