My car was scraped by a careless driver in a car park. He got out for a look and then drove off. A public-spirited witness left me a note of his registration, which I reported to the police. They said they could not prosecute him for failing to report an accident because it took place on private property where the Road Traffic Act does not apply. They advised me to pursue the driver through my insurance company. I am reluctant to do this for fear of increased premiums. Is there anything else I can do or has he got away with it?