Use a grinder!

Seriously,this happened to me a few years ago and the paint company hired a detail service to use the "Gumby" type clay bar to remove the overspray!

 

I didn't read all the post but clay bar! I never figured out anything that worked on glass.

 

A lot of time with a razor blade.

 

CLAY BAR.... should work.

 

Trust me, ALL of the insurance companies that insure paint contractors KNOW that clay will easily take water based overspray off. Urethane or epoxy, DIFFERENT story, but water based is easy.

 

Not trying to start an argument but I disagree. I never ran a fortune 500 painting company but I do have many years of hands on experience in and around body and paint shops. Acetone evaporates quickly and will not do any damage on a clear coat unless left wet and in contact for an extended period of time. On paint jobs that do not have a clear coat I would definitly say no way. I have used it on my own vehicles and have had no problems.