Abstract: A water repellent glass treatment for automotive applications comprising a windshield washer solvent which contains quaternary compounds, preferably siloxane based quaternary ammonium compounds, fatty quaternary ammonium compounds, and mixtures thereof which are dispersible in water, alcohol's and water alcohol mixtures and imparts a good degree of hydrophobicity to the windshield surface. The fluid is used in underhood washer solvent reservoirs and applied to the windshield of the automobile in the conventional manner and is packaged in diluted solution or a concentrate for addition to the windshield cleaner/solvent solution.