Thoughts on frustrating situation.

Bare with me , as I go over this.

My 19yr old son bought a 2016 Chrysler 200 s at the end of May. I co signed and we were "persuaded " into the premium extended warranty.10 days after purchase he calls me at 8pm on the side of the interstate , car told him to stop the vehicle and place in park, then locked itself in park.Long story short had to pay towing to dealer he bought it from,and 2 weeks later it was "fixed" and he picked it up, he paid towing and deductible. Fast forward to last Monday car does it again back at same dealer. They finally call this week it's a different issue with Trans so now their charging him diagnostic and they say it needs new transmission they are waiting to see if warranty will cover it. Then proceeds to tell my son he's not sure he can even get the transmission because they are backordered through Chrysler. But can get used ones. Any advice? Any legal responsibility to dealer?
Are you going to just ignore the obvious here? A 2016 vehicle, and supposedly a higher up platform for Chrysler already needs a transmission possibly??? I would run for the hills and say **** you to all the Domestic trash and keep your hard earned money in your wallet.