We have three cars, a Smart, a Saturn, and a Hyundai. This past month was hot here (high 80s, low 90s) and every time we got in any of the cars, we'd swear the other two were just as hot as the Smart if not hotter. We think the clear roof is psychosomatic (spelling?). It would be neat if someone did a temperature test on a hot day with a Smart and some other cars, and some thermometers.