Does the guy remember who he had insurance through for that car?? I've had the same insurance company 30 years. They could tell me the VIN off any of the cars I've insured through them.
Was he involved in any accidents with the car?? If so, there'd still be a accident report with whatever agency investigated.
He also might be able to go down to the local DMV and see if they can pull that car up under his name.
Just some ideas.
