How many of you sand or wet sand your color coats on a car model?

Yup, me too.  I use enamels and lacquers and still have the same problem.  Some of my pet theories:

- I’m using too small a nozzle on the airbrush.

- I don’t prep the primed surface enough.

- I use opened spray cans; a friend tells me to always paint cars with a fresh can.

- I REALLY stink at gloss finishes.

I too would find any advice to be most appreciated.

I've done the polishing thing and while the results are pretty amazing, I find it very frustrating as I keep cutting through the paint even with the finest sanding pads.  I've had pretty good success with Tamiya rattle cans - putting the wet coat on heavy, just before it runs (ya, I know...what is that).  I've heard great things about Testors wet look clear and I have some to try.  Couple folks swear by it.  I've also had success with Future for a final coat.

Couple kits right out of the rattle can:

This airliner was done with Future - one of my better clear coats

It is hard to get a perfect gloss on lacquer, because it dries so fast.  A final polish and waxing is the norm with it.

For a better shine with enamels, I do sand between coats, and add thinner to the mix for the last coat. And, I put the last coat on quite wet.  This does, of course, tend to run, so great care is required on that coat.  I do several passes for that last coat, waiting a minute or so between passes.