Any bodymen on here that can answer this, spraying the sierra and I want the finish to be second to none, its primed and all panels perfect, now usually when I'm prepping for paint I will sand to p500 and grey scratchpad, then paint, the finish is good but I was wondering if I was to sand further than that, e.g. Wet 800 grit etc, will the finish appear any better? And how far can I go with wet sanding (1500, 2000, etc) until the paint doesn't have much to grip to.
I may also add the paint will be pure white, mipa 2k so it should be good covering.

Any info is greatly appreciated.

Also I guess while I'm at it what's the best grit for flatting and polishing after paint, so I can leave a good show car finish and shine, thanks