Hell, sometimes not even months. Bought a new truck in Denver late July and had a crack across the windshield from a rock before I even got it home. Less than 100 miles on it and a broken windshield already. And of course, because it's a 2017 and a new body style, you can only get the glass from the manufacturer at a hefty price ($900, all said and done). I would happily pay double for a windshield that wouldn't break every time a rock hit it, particularly since CDOT thinks spreading small sharp rocks all over the road is an acceptable substitute for adequate plowing and/or salt.