Mothers® California Gold® Water Spot Remover is Designed to Remove Stubborn Hard Water Spots and Stains From Any Exterior Glass Surface. Powerful Mineral-Disolving Agents Scrub Away Sun-Baked Sediments, Salt Spray, Tree Sap, Road Grime, Bugs and Paint Overspray. Use Mothers® California Gold® Water Spot Remover on Exterior Glass Windshields, Windows and Mirrors.