Sold 15 year old truck off of craigslist to person 2 states away. Person looked over vehicle, drove it twice. I accepted his offer. Signed over title, buyer got in transit plate to drive it 5 hours home. Called drove great home, problem next day stalled a few times. I never had a problem with this. I do not have copy of bill of sale sold as is. Still considered as is sale?Person not asking for anything yet. should I be worried?