Well goo-gone didn't work yet.. Will try wax and tar remover next..
Was the paint always like that? I had my Mach 1 detailed by Mike Phillips of Autogeek.net when it was brand new (he was with Meguiar's back then). My car had overspray on top of the clearcoat on the trunk lid near the bottom of the rear window. We both thought it was missing clearcoat. Fortunately, when Mike rubbed some compound (Meguiar's M80) on the area, it revealed clearcoat underneath.
How Dark Shadow Gray overspray got on top the clearcoat, we couldn't figure out.
Rub some mild abrasive (polishing compound) over the edge of your panel. If you get paint on your towel and the area you rubbed looks the same, you've got clearcoat failure.