I have been using the Rain-X range for a long time. I used to apply it by hand and the results were amazing. This actually makes the surface of the windshield slippery, allowing the rain to magically slide across the glass surface just by the force of the wind. A friend told me about this Rain-X washer fluid additive that you put in a washer fluid bottle and every time you use the sprayers, the Rain-X solution sprays onto the windshield, saving me the trouble of manually applying it. What will they come up with next? Good product!