I use the spray on RainX but when the water beads up it is mesmerizing to me and I have to really concentrate on driving vs. watching the water bead up. It'* like an acid trip... not that I'd know what that was like but just assuming it would be similar.
The only problem I have is that I can't reach the middle of the back window so it looks funny. When my son comes home I'm going to have him take care of that problem. It sucks being short!!!