This was a spontaneous explosion of the rear lift gate window. The car was not even turned on; I had just gotten into it. There was a sound like a gunshot, followed by glass shattering both into and outside the car. I dropped immediately in the seat, and when I started breathing again, I got out of the car, and saw the window. Thanks to my grandsons research, I now know this is, and has been, an issue with the Acura RDX. There. was absolutely no warning prior to this occurrence.