[svxistentialist]

Earl is 100% right here Ahmed.

You need to take off the door panel to see it. it's easy enough to do, but don't force it more than you have to or you will break the embedded plastic pop-on clips.

There will be a runner or guide on the inside in line with that scratched line in the glass. The part that pushes the glass into place has a felt or velour pad up against the glass. This pad gets grit embedded in it. When it does, this grit abrades the glass each time it goes up and down, hence the scoring.

As it is on the inside of the window, my guess is that dust and sand gets down there when driving with the window open in the summer months. The outside of the window pane is "cleaned" by the rubber strip it is pushed up to, so I suspect little or no sand gets to that side. Most of the scoring damage will be to the inside of the glass.

A car that has been driven a lot with all four windows open will have scoring on all four opening panes. A car where the driver prefers aircon and windows closed will have very little damage to the other 3 windows. The driver's window is nearly always marked, it is just a question of how bad the scoring will be.

Joe