I use the ICE brand clay bar and wax the clay bar works pretty nice but there could be a lot more products out there that fill in small scratches. There are also special products for black cars. I've seen a couple that look like chap stick and you just rub it over the scratches for a touch up look if you go to a car show or something. I would try with some different clay bars etc.

 

clay bars dont do much..there really for cleanin over spray on paint or cleanin pain it general the dont rid of scratches like buffing will