I bought a used car here and it dies less than 18 ...

I bought a used car here and it dies less than 18 hours after purchase. While the car was at the side of the road waiting for a tow truck, someone approached us. He said that he worked at Castle Honda and could not believe we were sold the car. He suggested that we trade it in asap. When I spoke to the manager about the problem, he said that we signed a "buyer beware" form and they were not at fault.