I got mine knowing full well they're hot in summer (I'm in Australia), and impossible to keep clean (remember, I'm in Australia, we have lots of dust and not much rain to wash it off) and you're more likely to get run into because people are less likely to see you (yes, true, black cars are hit more often, the insurance company stats say so).
I got it because police are less likely to notice a black car speeding, and can't get a reading off it until a lot closer with a laser speed gun.
The human eye and brain estimate speed at a distance by rate of change of size. But a black car stands out less, so it is a lot closer before the brain registers that it might be speeding. And because less light is reflected off a dark coloured car it has to be almost twice as close before a laser speed gun can get a reading. So in a black car you've got a lot more chance of seeing the cop in the distance before he sees you, suspects you might be speeding, raises his laser gun, and gets a reading.
This probably doesn't matter in a tiny little place like Britain, but here the distances are huge, the speeds you want to travel at to not take forever to get where you're going are necessarily higher than the safety nazis want to allow you to go, the speeding enforcement is actually a lot tougher**, and they can hide in the bushes way off in the distance and see you coming.
** In the state of Victoria, which fortunately I'm not in, the speed cameras, red light cameras and the police between them collect an average of 100 pounds per licenced driver per year in revenue, and book one in three drivers per year. That's the equivalent of 3 billion pounds a year in speeding and red light fines in Britain. You guys, for all your whingeing, get it easy.