There have been previous postings on this topic, either here or on the Edmunds forum. Do a search for "clean windshield." You will see some unusual recommendations, including this one from "Big Foot":

My son is an autobody man and he showed (proved) to me that the silliest thing will work wonders with auto-glass. It's what he was taught in detailing class.

Use Windex or any other ammonia based window cleaner to get the heavy stuff off.

Then mist the window lightly with Windex or even pure water and use the Black & White pages of a newspaper to wipe the glass down.

Absolutely no streaking and the glass literally disappears with clarity!

I know it sounds dumb - but it truly does work!