Yeah, wet sand the paint, just enough to blend it with the rest of the paint and get rid of any imperfections. Very fine paper, lots of water, gentle touch.. A lot of people color sand after the paint is dry on a complete paint job to get the paint really level and smooth, then hit it with rubbing compound and a buffer..
The point here is to blend the fill job in with the rest of the surrounding paint. That's the cheap way to do it, and results may vary depending on type of paint, i.e. metallics, pearls, flip, etc..