First of all, I am a foreign student in US, so I don't know motor vehicle regulations very well here. If my questions looks silly, accept my apologies in advance. Recently a car hit my 2000 Ford Taurus from behind. The bumper is cracked and the trunk lid is bent which prevented the trunk from getting locked. Even though the accident didn't cause any mechanical damage, I was suffering from lots of other mechanical problems even before the accident. (leaking coolant, constant engine light which occasionally flashes, gray smoke coming out of muffler) Anyways, I received good money from the other party's insurance company and bought a new car. Then, I decided to get rid of my Taurus for a cheap price on Craig's List. Someone came to see the car. I explained him all the problems. I told him that I was using the car by adding coolant in every two weeks even before the accident. I told him about the engine light and gray smoke. He said that the engine light was most probably because of blown headgasket and it would decrease the value of the car considerably. Since I didn't know much about the cars, I didn't even argue on anything. He test drove the car and finally he said that he could repair and sell the car, and make some money out of it if I would sell it for a reasonable price. Finally, we settled down for $720. I received the money in cash. I signed the title and NY State DMV DTF-802 Statement of Transaction form (i don't have a copy of it unfortunately) , and gave them to him. We didn't sign any "bill of sale" agreement. I returned my plates and removed the car from my insurance policy in the next morning. Later afternoon, he called me and wanted to return the car because of the overheating problem. Since while selling the car I told him that coolant was leaking and he needed to fill it up every two weeks ( which i did in a whole year), I refused to take it back. Besides, i didn't want to take back the car since i didn't have plates and insurance on that car anymore. He still claims I misled him while selling the car, which is not true at all! He said he would sue me if i didn't accept the return. I'm super stressed after my conversation with him since this is the first time that I sold a car and i don't have any proof of transaction or "bill of sale" that proves that I sell the car "as is". I didn't even know this guy's last name! (He even refused to give me his full name on the phone.) Do I have to worry since I don't have a copy of Statement of Transaction form that I signed. As I said I already signed and gave the title, surrendered the plates and removed the car from my insurance policy. Do I still have any responsibility on that car? If he involves in some kind of illegal action with this car, can i be held responsible for it? Thanks for all answers in advance... I signed the title and filled all fields related with me, but I didn't see him while signing the title. So, I don't know whether he has his signature on it right now. I surrounded the plates, so my plates are not on the car anymore. I never gave him a warranty (written or verbal).