After many years of frustration trying to clean off my windshield on vehicles, and trying to get the road grime off, I found a gent and his wife who gave me their formula for their cleaner. They used to be truck drivers and traveled the country and sold a windshield cleaner in a 4 ounce plastic dispenser. Both are now retired, and when I asked what it contained, I was floored. It has 3 parts baking soda and 1 part creme of tartar, Period. So you can mix up a small batch and try it and carry it in a plastic bag. I wet the windshield, spread it on and use my hand to wipe the bugs ect off. In the rain, I just stop under an overpass, sprinkle some on and drive out in the rain and use the wipers. Works great for me. Does not scratch, and is biodegradable.