By way of Winding Road, I found this site. . . http://metacool.typepad.com/metacool/2007/04/thoughts_on_a_c.html The argument for a white roof is that it reflects more sunlight away from the car, thus reducing the need for A/C in the cabin. Sounds logical. . . However, I'm not sure if anybody has crunched the numbers to show whether it really makes a significant difference. My intuition is, probably not -- but I could be wrong. Every little bit adds up. (On Winding Road, somebody commented that if you really care about that, you'll just get a white car anyhow.) I did find this first photo striking. . . Can anybody identify what kind of car that is? It's interesting because it has a lot of efficiency cues. Not only the white roof, but also the fastback shape which reduces aerodynamic base drag, and the covered wheel wells, which again reduces drag. I also note the lack of sharp creases or "accent llines" on the body which would disrupt air flow. It's obviously an older car, and the proportions are all wrong by today's standards (and the rocket nozzles are hilarious), but it's a curious thing to see these old designs where they were putting more thought into efficiency than today's cars.