Nearly all car owners have had to deal with water spots on their windows. These spots are caused by hard water, which refers to any water with dissolved solids in it. Calcium is one of the most common of these and is responsible for untold numbers of hard water spots. Rainwater sometimes contains enough calcium to cause spots.
Clean the glass with water and a new microfiber cloth. Fill a bucket with water and dip the cloth into it. Ring out all the excess water and wipe all of the junk off of your windshield. This will ensure all residue and dirt are removed.
Put a small amount of the glass cleaner on a separate microfiber cloth. Do not use the same cloth that you used to clean off the dirt and residue. This cloth is likely quite dirty and the water may weaken the glass cleaner. Use whatever amount the manufacturer recommends, as the amounts vary from product to product.
Rub the product into the affected areas of glass using small circular motions. Do not use up and down motions. This will smear the cleaner. Continue rubbing until all of the spots are gone.
Wipe the residue of the glass cleaner off the windshield using a new microfiber cloth. Remove all of the residue, as it will leave streaks if not cleaned off.
