when i drove from AR to NY, I hit a heavy rainstorm, I had the 2nd rainx product displayed. It actually saved me because my driver side wiper decided to get stuck off the windshield (first I knew of my wiper system failing). This was also at night. It kept my windshield clear enough to pull over and wait for the rain to pass.
Without it I would've likely been on the side of the interstate in a tree.