Apply WaterSpot onto the desired surface and wipe away with a clean microfiber towel. If you still have water spots, Gyeon does recommend reapplying a few times for best results and more vigorous wiping. Gyeon does share a warning: "WaterSpot might affect the hydrophobic layer of a coating. It's dangerous to leave the product on the paint and especially on glass for a long time." With that advice, we always recommend applying this product in the shade and once finished washing the area with a car wash shampoo like the Gyeon Bathe or Bathe+.