While driving on highway i-5 car started jerking and did not want to accelerate when i put my foot on the gas. i pulled over and restarted the car it would not go in gear and moved 2-3 miles an hour at a time. tried putting it in reverse and would not move at all. i was not far from dealership so on the highway with flashing caution lights made it to dealership. the car has been with the certified gm dealership for 6 weeks a 2016 cadillac xts with 1400 miles dealership mechanic states car needs a new transmission. gm has yet to make a decision and want to put a rebuild transmission in the car. there has to be a factory defect that jeapordized my safety and others safety on the highway that gm is not willing to acknowledge.