Call the police. They can probably tell you and they will appreciate your contribution.
How Can I Check If A Car Is Stolen, If I Only Have The License Plate Number?
Pb 31c 5341
Perhaps you can't, but the Police Department would probably love people like you. If it is stolen your information would show up in their records if the car has been REPORTED as stolen.
call the dmv or the police and let them run the car on the system. Tell them that you suspect the car is stolen
If you are intending to buy the vehicle, it may prove useful to carry out a HPI or Experian check on the vehicle. For a small sum, they can check to see if the car is stolen or has an outstanding finance arrangement on it. See www.hpi.com or www.experian.com for further information.