Consider the fact that on some auto racing circuits, the racers prefer to use lexan instead of glass for windshields.
While I already have one scratch in one new Polycarbonate [lexan] window, done by impact with jaw of spin pole, all it is is a scratch.
looking at my old set of windows ... there were no scratches just 27 years of cleaning the outside surface with all the wrong chemicals. The insides were fine.
