GRASS Anti-Rain Windshield Washer Fluid Additive
I decided to test this Grass product. I didn't think it would be effective for the price, but apparently I was wrong. It works great even after three washer fluid reservoirs. The effect lasts quite a long time for the price. It works at speeds of 85 km/h (53 mph); the higher the speed, the faster the droplets accumulate and fly off the windshield.
You can buy it at almost any store; it costs between $1.50 and $2.50.
Grass product code: 800440