Actually, I've been thinking for a long time about building a swamp cooler for my civic. I think it'd be easy to make out of fiberglass and PVC to fit right in the sun-roof... I found a how-to page on this once, and it seems pretty easy. If I ever do it, I'll post pics etc. It ads a little drag, but it's a good way to cool the inside of the car without losing too much HP from running an A/C system.