Contrary to popular belief that black cars require less maintenance, I would have to say that it is totally not the case. I found myself spending more time cleaning it than my former car, which was white. It is really tricky to keep it clean because it is almost deceiving that it doesn't need cleaning since it is dark in color.
The problem occurs when white spots and light dust start to surface. If you don't take care of these immediately, then expect your black car to be covered with dirt that will not only make it look bad, but it would jeopardize its coating. Here is a quick and easy tutorial on how to keep a black car clean.