im not happy!!!!!!!!!!!!!!!!!!!

well as i said i sold my porsche 99 12000miles,the person who bought it from me took it to the local porsche dealer and there saying there is $5,000.00 of reparis TO THE CAR!!!!!!!!!!!!!!!!!!!!!!!!!!! i dont know how becasue the car always ran smoothley and never had problems when i drove and now he wants his money back and im going to have my car back with $5,000.00 of work that needs to be done