in the 50's we cleaned windshilds at the pumps, some "BonAmi", (scouring powder). "Bar Tenders Helper" or a few others. Now i keep some "Comet" in the trunk. works great for road film.
a folded mecnics rag, wetted, sprinkle on rag and scrub the window, turn the rag to a clean side and wipe clean.
