I'm replacing the regulator. A helper smeared some goop on the inside of the glass. I think that this side has plastic tint film. I suspect that the goop is either the black tacky stuff that holds the moisture barrier in place. Or, the goop is the movement-retardant "grease" that holds back the window regulator cable.
I can't manage to get this stuff off the glass. I've tried two different glass cleaners, isopropyl alcohol in 70% and 90% strength. The 90% isopropyl at lease lets me push the stuff around on the glass with paper towels. Really inefficient.
What's a good liquid to use that will remove the stuff and not damage the glass coating? Any special technique?