I just came back from the shop because my rear window disintegrated. We were driving in the rain at night, I looked back and told my wife that it seemed my rear window defroster failed. A few minutes later there was a POW! We didn't feel anything, it didn't seem like anything fell on us or that we ran over anything, but I pulled over and checked anyway. Nada. Get back in the car, close the door- and a big piece of the window blew out from the center.
According to the shop, this is becoming less uncommon. These safety glass windows are slightly stressed curved forms when installed. And like Corelle (and other material types) it can be very strong until enough scratches and pits disturb and create stress lines. Eventually (25 years) just a little pressure (cold and rain on the outside, electric defroster on the inside) can overwhelm the integrity of the (scratched up) outer layer, and you suddenly have a delicate plastic film with tiny pieces of glass on both sides.
He had a few stories of 12volt hair dryers being used as defrosters, and blowing up windshields. My new rear rear window is a LOT clearer than my old one.
Tho I still have a very soggy trunk to deal with.