On the Original Smart Fortwo, the 1998-2007 "Type 450" model, the rear passenger side has a revese light, but the rear driver side has a red rear fog light. In Europe most if not all cars have rear fog lights. You can turn it on if it's really rainy or foggy, it's a very bright red light, but I hate it because the dash light for it is also a super bright red light that's very distracting. And also people tell me every time I back up that I have a reverse light out, which I don't.