I just found and read this article in the Lodi-Sentinel, from their staff; in Lodi CA: Helpful tips to prevent ice on your windshield.

It mentions one idea I gave earlier about using table salt to melt and remove ice from your windshield.

While I mentioned also that you can seriously scratch your windshield by using metal items like a kitchen spatula, they claim that a plastic spatula could work in a pinch. Being plastic they most likely are correct.

Also they mentioned that a credit card could be used. Talk about frozen credit.

Some other things to note. They state that by placing floor mats or cardboard over your windshield, that you could simply lift them off with the ice. I have known of some that have tried this only to find in the morning that the cardboard or floor mats were frozen to the windshield because water had gotten under them. Trash bags are also mentioned and it may work. That idea involves putting enough bags together with tape to stretch across your windshield and then holding them in place by closing them in the front doors.

Aquapel, Rain-X and other windshield treatments aren’t shown in this article, but experience has shown me that these products really work at helping to remove ice. My better half has informed we she won’t drive her car unless it has been treated. Their only draw back is that they must be applied on dry auto glass with temperatures above 50.

A word of caution is stated here also, not to use hot water or heat the windshield up fast as it could crack it. This would be very true if the windshield had a chip on it.

The whole article can be read by clicking here: Helpful tips to prevent ice on your windshield