Just got my C320 in black. Can anyone tell me whether there is a clear coat on top of the black paint?

Yes,

Most newer cars today have clear coats. If your car came factory then yes it does, even if you get it repainted, I am sure there is clear coat on there.

One way you can tell is when you buff it. Most older cars that do not have clear coats when you wax them, the color of the paint is on the pad, if that is not the case then its clear coated. Also non clear coated cars seem to get oxidized much faster.