Environmentally friendly way to get RainX effect on your windshield.
1.) Cut a potato in half.
2.) hold the exposed (cut) portion of the potato against the windshield and wipe it all over your windshield. The starch in the potato will act as an invisible barrier between the windshield and the rain.
3.) Repeat as necessary.
I have used this before and it worked as well as RainX, however I am not a big fan of the RainX effect. For those that do this is an inexpensive and environmentally friendly way to get similar results. I searched for information on what is in RainX and found special polymers. The vagueness of the description makes me wonder.