if you're using a drill kit, more than likely that is your problem. i don't think drills have the rpm's needed to polish out stuff like a bench polisher. i bought a drill kit just to do a set of wheels, and it was a waste. i ende dup buying a big motor and flex shaft instead. the left one is polished, the right one is what they looked like before.
the drill kit was literally a waste of my time, i would suggest getting one of the flexshafts on a bench polisher IF you don't have access to a compressor/die grinder ( i do all of my work in the garage in a subdivision, a compressor would be too loud)