the DVLA shouldn't be giving that out to anyone but the police as far as I'm aware.
Providing you have 'reasonable cause' then joe public may be granted details:
Examples of reasonable causes for obtaining the information:
- To trace the keeper of an abandoned vehicle or vehicle involved in a minor accident (for example, if a car has been driven into and damaged another vehicle, then been driven away).
- To trace the keeper of a vehicle which has been driven away from a petrol station without paying for fuel, or which has been driven without payment of a toll bridge or tunnel.
- To trace the keepers of vehicles that have been parked on private land without paying the parking charges.
- To investigate suspected insurance fraud.
Doesn't help you to find previous owners though.