uh, from what we used to do to the cars at the shop after painting and couple of clear coats (wait like half a day), was a Smooth Water Sanding over with very fine grid sand paper, after that, wax and polish.

Oh yea, make sure u're watering and sanding at the same time. DON'T SAND THEN WATER

The part of Wax and Polish was to make the spot's color match with the rest of the car, because you know how new paint job stick out like a soar thumb.