While driving, my Audi overheated randomly, started smoking, had to be towed. Had 72,800 miles, was serviced by Audi at 70k miles and all prior recommended services. Towed to Audi dealership, quoted 29k in engine repairs, Audi could never tell me why engine overheated. Would not cover any expense because i didnt buy it there. Insurance denied two claims because Audi reported it as engine failure although they couldnt prove what happened to cause the heating, said it was one of the worst engine overheating they had seen. Prior to overheating, service driver system popped up for the first time. Temperature gauges were normal. Will not start or run since. No accountability taken by Audi at all, even through corporate. I believe my safety was at risk because the engine would have caught on fire had I not of noticed or pulled over. A Good Samaritan even pulled behind me to check on me because they saw it smoking in passing. I have a video of Audi inspection. Date is estimate of event, I would have to research. Vehicle was purchased by prior owner as cpo from Audi at 30k miles and serviced since at same Audi dealer every recommended service and prior if issue arose, I have all service records.