I didn't think of it at the time, but a while back my wife parked at the local supermarket, and while she was sitting in the parked car, the car parked in the spot in front reversed back into her. You can clearly see on the dash cam that my wife was stopped at the time, and hear my missus honking the horn at the sheila in the car in front of her before she hit. My mrs got out and gave the woman a mouthful, and pointed to the dash cam in her car.
I don't know if it was an attempted scam, but there was bugger all damage done to either car, just a scuff on the wife's roo bar. But the woman didn't have her drivers licence on her, and gave a false name and address anyway, as we found out when I googled the address.
Goes to show though, that it does pay to have a dash cam.