classic33
Leg End Member
The registered owner has to say who was driving at the time, if it wasn't them. Otherwise you proceed against the registered owner/keeper.You have reasonable cause to find the registered keeper from the DVLA.
When you are writing up your account of the incident, write up as much as you can of the driver's description. That will stop him telling the police that he lent the vehicles to a few mates over the time of the incident.