how do I get my #$%@##$%^% windows clean?

I was the Quality Manager in a PPG (ex Chrysler) automotive side glass plant. To remove fine spots from our processing we used vinegar in our wash (smelled like a pickle factory on bad days), very fine steel wool or 6000 grit sand paper. I know the sand paper is expensive and hard to find but this is what must have been the best methods as it is what we used. Our plant closed (Evart MI) but I found a way to get enough of each of these to keep my Barracuda windows like new.