Got it. Then I would try to get the dealer to look at it under warranty....having grease get on the windows is not normal, so I would argue that it's a defect. I'd worry that the window is rubbing against something that it's not supposed to, and that you'd have other problems show up later.bstboy said:Cleaning it is not the problem. It happens every time I roll the window up and down. I can clean it but the next time I roll the window down, there it is. Obviously something within the door itself is causing this. The streak is on the forward half of the windows.