Years ago I used to dabble in model railroading. One of the products I have a few oz. left over is useful for removing paint from plastics without damage.
Today I did some spray painting while wearing poly carbonate glasses. I couldn't remove the paint spatters (dried latex) with water and I sure wasn't going to douse the glasses with lac thinner so I tried my old standby.
Because the plastic bottle broke years ago, I had transferred the contents to another bottle so I can't recall the EXACT part number. It looks like Floquil "Easy Lift Off" is the current description of the same stuff I purchased back in the mid 80's.
Here is the link:
dave