Interested in peoples thoughts on this one.... I have used 'Rain Wizard' for some time, applied to the outside of the windscreen. It causes the water to bead on contact and at speeds above about 55 - 60 wipers are not required! the water just flies off. Recently though my wipers had a really hard time on it, juddering horrifically in all conditions. The problem was solved when I replaced them, though they were only about 6 months old.
Anyone have any experiences of this stuff, and can ayone recommend better products?