I went on vacation only to return to a serious splattering of concrete on the passenger side of my car. It was thoroughly dry by the time of my return. I’ve scraped of much of the smaller spots with a worthless credit card but the bigger chunks won’t budge . . . suggestions please?!?!
I’d take it to a detailer. Doing it yourself is risky, and everytime you wet it the concrete becomes stronger and more tenacious.
I believe Tom and Ray answered this question over the summer. IF it is just the residue from the concrete they suggested using a diluted muriacid, like the stuff you put in swimming pools. For the big pieces use a better scraper/spatula. Make sure it’s made out of plastic. Try the acid on a small area first.
I remember that show. When they called the guy back on Stump-the-Chumps he said it worked like a charm and did not harm the finish at all, but as suggested above, try on a small test area first.
This company: http://www.safe-react.com/conrem.htm, claims that their product is better and safer at removing concrete, from various surfaces, than muriatic acid.