i actually had the same, i reversed into a parked car once, just clipped it, left a not on the windscreen telling them if they have any damage (i couldnt see any) take pictures and contact me and il reimburse the cost to repair etc. They rang their insurance, told them id hit the car and they wanted it repairing (again... there was no damage, just a black scuff mark that rubbed off) my insurance paid out a very small amount.
16 months later i had a letter saying i was having a claim put against me for whiplash.
best part of it, no one was in the bloody car at the time!!! id luckily taken photos myself of the letter that id put on the window, the scuff mark and the overall "accident". My insurance refused to pay them, they took it to court (i didnt have to attend or anything) and they didnt get a penny!
people are just scrounging gits, always trying to earn a fast buck!
These people should be prosecuted for fraud.