2015 Hyundai Genesis body & structure problems

My wife and I just recently purchased 2 2015 hyundai genesis coupe 3.8 auto. This is a 3 month old car with 2700 miles. I took in once for squeak in rear area, they said could not hear it. I advised I would take tech out so he could hear it. They said they were to busy. Took back a second time, they said they could hear it, tightened everything in rear area abut could not find problem that may have broken weld!! They could not give me a loaner.

While driving on expressway at normal highway speed we heard a very loud noise, and a few seconds later the head liner of the car started to flap due to wind interference. We soon realized that our sunroof was broken. Glass shards were mostly held back by headliner. However, some glass shards fell into passenger compartment. We were not injured. We stopped and saw that the remaining glass pointed upwards, and that the sunroof window frame did not seem to be bent.