Well hell I din even know they made something to fix issues like that. I thought that I was going to have to eventually replace the original windshield in my 71 Stang. Something I have avoided for years because at some point long before I owned it someone let the wiper arm wear a scratch into the windshield. Not deep but noticeable enough. Gonna have to give this a whirl before I replace it just to see if it is salvageable.
http://www.powerblocktv.com/two-minute-tech/2min-27/resurface-scratched-auto-glass
http://www.powerblocktv.com/two-minute-tech/2min-27/resurface-scratched-auto-glass