sold a car as is on facebook, the person who bought it said two days later it got hot on them and that it was a car at a auction, i have owned this car for four years. told them it had my name on the title no auction car, then they texted back and said a garage told them a thermostat probably stuck open, then a week later they texted back saying it overheated and they are going to sue me, is there a law to protect the seller or do i prepare to go to court