Possible Fraud?

Hi
Im planning to sell my car to a dealer in Wimbledon(Wimbledon prestige cars) who is transferring money into my account. But he is sending a buyer he has organised to collect the car so the V5c will go into the buyers name. What is to stop the car dealer from then turning around and saying the guy who came to collect the car and register it in his name had nothing to do with our dealership- give us our money back!!
Should I insist that the V5 be in the dealership name? Or should I get something in writing and will it hold up in court?

thanks to anyone for their advice