organic chemistry - Ethyl alcohols use on polycarbonate and acrylics

I have an interesting question about the use of ethyl alcohol on polycarbonate windshields. I have had friends asking me about the use of Pledge Multi-Surface cleaner on their windshields. Some insist it will degrade, yellow, or even crack and soften their windshields. Others have been using it for years with no apparent effect.

Pledge does have a small amount of ethyl alcohol, but does it have enough to degrade and ruin motorcycle windshields or does ethanol do any damage anyway?

Pledges' MSDS states ethyl alcohol weight at 0.01-1.00 (http://www.scjohnson.ca/pdfViewer.aspx?pkMSDSId=367&language=en).

So what are the effects, if any, on using this cleaner on polycarbonate windshields?

Thanks