I went for that "retired race car" look - bare aluminum and flat black:
I would have left the foot-boxes bare fiberglass (like original) but I had to modify them to make room for the 351 Cleveland. Ended up painting them black to hide the modifications.
I thought the bare aluminum might get too hot in the sunlight, but, it turns out the flat black parts get the hottest. No carpet, no mats, insulation on the footboxes and underside of the floorpans.
regards,
Jeff