I used 1400 grit wet sandpaper to polish up the clear coat after I paint, I would suggest to practice on a piece of the old bodykit that was removed.
I had a Aerokit put on mine, so it gave me a bumper to practice on (underside) before I attempted to touch-up the nicks on my back bumper, after you wet sand you will end up with a white patchy looking area that will buff out after you put your polish on. But do it in stages, do not try to remove it all at one time or you risk going to deep.
just my .02
