Sorry to hear about the incident, it's ridiculous that people just drive off thinking they'll get away with it! I just hope the police can find the car and owner and that she has to pay up for it. Glad to hear that two witnesses caught most of her reg no, some nice people out there!
I had a similar thing parked in a shopping centre, car was parked up in an end space, but it wasn't a car that hit me, it was a female shoplifter who supposidly "ran into my car" and debenhams said the CCTV was not working at the time, and the police when they arrived to arrest the female shoplifter turned a blind eye to the damage on the car saying it was an "accident". I ended up having to pay up, becuase I threatened to take her to court over it and was told by the police that records show she was unemployed and homeless so there would be no point fighting it.