Looks like one of the window rollers are greasy. Front passanger side. I cleaned a couple of times and shows up again in the same spot. A mild annoyance but I'm curious if anyone had anything similar.
Never had this issue on my Prius, but have on previous cars, as have friends, so it's fairly common. There are typically 2 felt pads that the windows rub against as they go up and down, that can get dirty and cause streaks. Dealer should replace under warranty.
If you want to fix it yourself the door panel is easy to get off: http://priuschat.com/forums/gen-ii-...troubleshooting/6593-removing-door-panel.html
No need to dismantle, just wind the window fully down and clean the inside of the seals with a cloth soaked in windscreen washer fluid.
The felt or "fuzzy" as some people call it, is lubricated from the factory with silicone (and if you ever need to do it yourself, that is what you should use). Problem is, that is what causes the streaks. The rubber needs to be lubed deep in the channel, not out on the fuzz you can see. And it should NOT be lubed at the bottom where the door panel is, only the top and sides (sometimes down in the door too). FYI
