1. Start by calling the car’s owner and telling them that you think their car is defective.
  2. Tell them that you have evidence that their car is defective and that you want to return it for a full refund.
  3. If the owner is unwilling to refund the car, tell them that you will take it to a mechanic and have it fixed or replaced if necessary.
  4. If the owner is willing to fix the car, tell them that you will pay for the repair or replacement yourself.
  5. If the owner is not willing to fix or replace the car, tell them that you will take it to a mechanic and have them do so for free if necessary.
  6. If there are any problems with your return, be sure to document everything in writing so that future disputes can be resolved easily and efficiently.