I got a little overspray when I masked off my cowling because my Great Planes masking tape came unstuck when it got wet with paint. I am using Lustrecote spray. It is a very small amount but in several places and it is black smudges over white. Paint thinner won't touch it. Anybody tell me what you use as a solvent? Or do I have to respray the white area.

Use a q-tip and some a bug and tar remover. It will be strong enough to remove the paint from the clear but not the clear.

I used a q-tip and scrubbed with bug and tar remover--didn't even phase it? Anybody got any other good ideas?

You could use acetone. Get it at any hardware store. But be warned. It will attack most paint or plastic. Use very little on a q tip. And you may have to spray a new clear coat on your cowl.
Cheers

Try a product called "Oops!". You can get it at Wally World or Lowes. Usually in the paint dept. Works VERY well and even smells good. It's very gentle on plastics too.