On page 5 of the bulletin WhiteXKR posted above, point number 2 states the gap needs to be 89mm. I have fixed this issue multiple times, and think that gap is the cause of it. On my car, a gap of 89 looked like the panel would pop out so I am closer to 88. But what I think has happened to me in the past is that the bolt that is shown as point number 3 on page five was not tight enough and the gap shrunk (the last time it happened was when I let my kid sit back there for a ride around the block). Too small of a gap leads to binding and the panel not retracting the way it should. If it does not retract, bad things happen (I had to rebuild the track on mine with JB Weld original and a Dremel tool) . If you want piece of mind, once you have the correct gap and the bold tightened - it would not hurt to drill another hole in the bracket and put in a self taping screw. I would also check to make sure the other side of the panel is secure and not moving. Which should be the case - but if you are not the original owner of the car - who knows who worked on it before you? There is a bolt on that side that you have to go over a hydraulic rod to tighten - just make sure pushing on that side does not shrink the gap either.

 

Now I had time to repair the panels.
The angle of the plastic sticks were not correct, so I fixed it with some nails, opitimized. By repairing the small seals and greasing the slides with silicone spray. They are working nearly perfect.