Each night, spray your windshield with a solution of vinegar. Mix three parts vinegar and one part water into spray bottle. Take the mixture outside and spray it liberally on your windshield, side windows, and rear window. Then wipe down each window with an old rag or squeegee.
If you forget to do this the night before, no worries, The solution dissolves on contact so spray your windows and get help from your windshield wipers. Never use scalding hot water as your windshield is sensitive to quick temperature change. Hot water combined with excessive pressure on the glass from scrapping could crack your windshield.