I'm seriously starting to believe that the windshields are weak on 5th gens. A few weeks ago I got hit with something so small I couldn't even see it. It made a barely audible click when it hit the windshield. I was shocked to see a small crack. A few days later, I was at work driving a 2011 Suburban. I got hit with a much larger rock. It made a loud sound, but no damage. Last week, again in the Suburban, I saw a 1/2" rock flying toward the windshield. I actually ducked, thinking it might come through. It made a huge pop when it hit. I stopped and inspected the windshield, and again, no damage! A couple days ago, after having the crack repaired in my T4R, I parked in direct sunlight on a 70 degree day. When I came back, the crack had spread all the way down the windshield.
So now I'm out at least $400 to replace my windshield. Texas does not require insurance companies to cover glass, and I don't think its even an optional add-on. DAMN!! Considering that the windshield angle in the Suburban is pretty much the same as the 4R, I have to conclude that this is an issue with the quality of the glass. I'm no huge fan of GM, but they seem to be using some far superior glass!