HOW TO CLEAN A WINDSHIELD
Unfortunately, those once-in-a-while squeegee wipe downs we give our windshields while we're waiting for the gas tank to fill up do not count as "deep cleans". Even if your car has recently been washed, try to think back to the last time you cleaned the dirt and dust magnet that is the inside of your windshield.
A dirty windshield can not only obstruct your view while you're driving (especially in direct sunlight), it can also make an otherwise clean car look like it's way far overdue for a wash.
There are several reasons your car's windshield ends up so dirty. On the outside, you can attribute it to bugs, sand and dust, rain, smog, and other environmental contaminants.
Off-gassing is the main culprit in dirtying up the inside of your windshield. This occurs when that "new car smell" on your interior plastic and vinyl components eventually breaks down and evaporates, leaving an oily residue on the windshield. This haziness can get even worse if you've previously used oily cleaners on your dashboard. To learn how to properly clean your car's dashboard, click here.
Though they may get the job done for household glass cleaning, ammonia-based window cleaners are not the best way to clean your windshield. These products can lead to permanent damage to plastic, rubber, and vinyl. You should also steer clear of scrubbing products that are abrasive, including paper towels, newspapers, and scouring pads.
Simple Green Glass Cleaner is free of harsh ammonia and phosphates, so it restores shine and clarity to windows without damaging them. The ready-to-use formula cleans your car windshield by removing fingerprints, smudges, dirt and dust, and other grime to reveal a crystal-clear shine.
Clean your car in a shady area, if possible. Parking in the sun dries your car quickly, making it difficult for you to spread water and product around.
TIP: Don't forget to clean the rest of your car windows after you've washed your car - see how here.