I have tried it too... I applied water marks remover and the Nano Glass coating for my Vios windscreens. I used up 1 bottle of the Nano Glass for front and rear windscreens, plus left and right side mirrors.
I only got chance to test it during light rain on Saturday night, the effect was very good and I did not have to use viper at all. I drove quite slow, around 60km/h. Could see everything via the windsreen very clearly...
I'll test it when heavy rain comes

Added on November 16, 2010, 4:14 pmThumbs up for the RainAway water marks remover and Nano Glass!
It rained heavily yesterday, the coat did performed very well!
No blur screen anymore. When wiper was used, the water was cleared very quickly, so I only used the wiper at the lowest speed although it rained heavily. That was in the traffic jam. I think if I got chance to drive faster, no need to use wiper at all.
I will apply it on the windscreens of my other car this week and will recommend it to my friends definately!
Thanks, bro.
This post has been edited by BBLow: Nov 16 2010, 04:14 PM