2020 CADILLAC CT6 Wheels Problems

The vehicle was shifting harshly and my wheels were experiencing lock up while in motion which was very dangerous. I experienced this on the parkway as well as streets and almost had a few accidents due to this problem. I drive my wife and children in this vehicle. Our safety and lives were put at risk. There were no warning lamps to advise of troubles. I also have some computer problems that are supposed to be addressed. Gm dealer has had my car for four months and have tried to replace valve four times and all four times the part they received was defective and unsuccessful. I have made many calls to GM and they are giving me the run around. Now they want to replace the entire transmission but wanted to use aftermarket part which more than likely is also defective. They are having a hard time obtaining a...