[brainanator]

I think that's going to be really tough....many thinners eat into the plastic and weaken it badly. If you try to mask off an area and use a solvent, the solvent will just dissolve the tape/mask adhesive too, so that won't work at all....

I don't really have a good suggestion myself...sorry. :( good luck, and post up if you succeed. I wouldn't want to see that nice paintjob ruined though.