guys, I have a simple solution for this. buy a very fine sand paper, 2500 grit for example. link at bottom of message. use with gentle hands on the wet surface to clean it. I have bought it on ebay. only caution, use with water, not dry, and with light hand. it will clean almost all the spots on automotive paints.
but guys, caution must not be missed.
Matador Waterproof Sander Paper Grit : P2500 | eBay