I was traveling at the legal speed limit of 70 mph on the freeway with no vehicles within 50 yards of my vehicle in all directions. I had been driving for about an hour and was on a bluetooth connected phone call through the car speakers when I heard the sound of glass popping and shattering over my left shoulder. First, I looked in the rear view mirror to see if the hatch window had shattered, but it had not. Next, I looked over my left shoulder at the driver side quarter window, the vehicle only has two seats so there is no back door window, and saw that it was completely shattered but held in place with the protective film car windows are required to have. I existed the freeway the first chance that I had, and pulled into a lot to inspect the window. There were no indications of any entry projectile such as a rock, debris from the road, or even the remote chance a bullet or BB from a BB gun. In other words, the window had just shattered on it's own. I was able to purchase clear packaging tape to put over the entire exterior surface of the window so that I could continue my drive home. I still have the shattered window that was replaced on the vehicle and was able to inspect it again after it was removed from the car. Again, there were no signs of anything hitting the window causing it to shatter.

- Rochester Hills, MI, USA