How to Make Your Own Anti-Fog Glass and Windshield Spray. You can make an inexpensive anti-fog glass spray to keep your bathroom mirrors and the inside of your car's windshield fog-free. This solution keeps condensation from collecting on these surfaces.
Pour 2 ounces of white vinegar in a medium sized bowl.
Add 1 quart hot water.
Dip a clean, lint-free cloth into mixture.
Lightly wring out cloth.
Wipe mirrors and the inside of car windshields with cloth.
Allow to dry.