Clay bar works
I have been running a clay bar across the paint on the old chevy. I did some spray painting in the garage (chevy's underside) and some overspray got on the paint. You couldn't see the overspray, but you could lightly feel it.
Clay bar + quick detail spray = problem gone quick
First time I have ever used a clay bar, these things are great. You can feel the stuff coming off the surface, the amount of crap it picks up is amazing. Cleans off the chrome, and other metal trim too.