Engine Cooling System problems of the 2000 Cadillac SLS

Good morning;I had purchased a 2000 Cadillac seville(sls)used and the car shut off as I was driving on a major highway. The instrument panel (digital)started flashing engine is hot,vehicle engine must be shut down. The car started loosing power and I was able to steer off to the side of road. I'm not sure if the engine would have overheated and caught fire or not? I returned this vehicle to used car dealer for refund. I was told to take it to a garage and I discovered the radiator cap was leaking. It was replaced. To me it looked like it was warped? also I was told the fuel sending sensor was defected ad gas tank would have to be removed,so I returned the vehicle to dealer. He accepted to take car back. He took me to see a 1999 Cadillac seville(sls) and we discovered this car had the problem of running hot. I think maybe there is a need to recall this model of Cadillac for these problems and this would be a safety issue. Any questions, contact me. I would love to have the car that I purchased and returned, but the dealer will not fix the problem(s)because it is being sold as is. Please look into this matter and are there any recalls? thank you!.