For those of you who have never tried RainX, you should give it a try. This past Sunday, I had to drive about 5 hours in the rain (mostly highway) and I probably had my wipers on a total of about 45 seconds during that entire time. RainX makes your windshield so slippery, that even at speeds as low as 20-25 MPH, the rain just slides UP your windshield and over your roof from the force of the air hitting it. At highway speeds, it just flies off your windshield! You need to take a couple minutes (really only 3 or 4) per week to reapply to get the best consistent results, but it's worth it. After a while, you'll find wipers to be distracting and realize that you see much LESS well using wipers than using RainX.
Years ago, I also found out by mistake that those "once a year car polishes" like Polyglycoat do virtually the same thing to the windshield and actually last a bit longer than RainX, but they take longer to apply too.
Joe