1 After you wipe the paint, check the rag to see if you can detect any paint residue. 2  While you’re at it, make sure the residue isn't the color of your car’s paint. 3  If your car windows also got tagged with spray paint, acetone and a razor blade should clear it up easily. After you wipe the paint, check the rag to see if you can detect any paint residue. 2  While you’re at it, make sure the residue isn't the color of your car’s paint. 3  If your car windows also got tagged with spray paint, acetone and a razor blade should clear it up easily.