I've used #40 on my wipers rather frequently. As long as you put it on lightly and buff it off, I get no streaking at all. It will leave a tiny line on the windshield where the wiper sits, though (nothing permanent). My wipers are about 1 1/2 years old and they still work great. I put new wipers on the wife's car at about the same time and they are still holding up well too (her car isn't garaged). I also bought ACDelco wipers after constantly replacing the various kinds from the auto parts stores. They weren't any more expensive, but they have held up very well.