i uses Prestone silicone spray in the yellow bottle. i think i got it at walmart.. works pretty good for me.. i use alot of it when i do the channels.. it does nothing for noise though. the pass rear window i know is the regulator. ive replaced it once and its doing it again so i dont use the window. ill lower it enough to spray around it.. i think wd 40 dries out the rubber.. i wipe the silicone spray off the paint and the inside door panel..