NHTSA Complaint #11512133 — 2017 BMW 340I

While driving down the interstate I-65 South, my sunroof spontaneously exploded. It sounded like a bomb explosion inside my car and could have caused grave danger to myself. There was nothing dropped on my sunroof as the screen remained intact and closed with no damage. This was an upward and out explosion of my sunroof, which I feel is a defect and should have been the responsibility of BMW. However, the car manufacturer is prepared to charge me $2,719.05 to fix. This I believe is a defect. How does a sunroof explode spontaneously? Please help.