Try lubricating the tracks and all the rubber weatherstrip with silicone. Take a rag and douse it with silicone spray. Using the soaked rag, wipe down all the window tracks and the bottom weatherstrip on both inside and outside of the window so that all the tracks and the weatherstrip are nice and silicone-ey. It will take three or four treatments because the first couple of wipes will only wi[pe off the grunge. Don't use silicone paste/gel, only use the spray. This totally fixed it for me.