Pic of the front window track.
Can see scratch marks where I used pliers to widen it. I also angled it slightly just as ahdoman mentions above.
All this was written up by "Phines" several years ago. He had pics as well.
It relieves/reduces the friction between the glass edge and the rubber molding the glass fits into, so it won't bind/"pinch" and slow down the upward movement of the glass.
Many owners have had the window MOTOR burn out after years of it trying to raise the glass against this friction.
![]()