Saw this thread and It reminded me that I need to fix the wifes Cargo Cover. https://www.jaguarforums.com/forum/x...-cover-251319/

She had the rear window tinted and they lost the front tension clips. After ordering new ones it would still drop after the slightest bump. Poor design breeds invention. It appears as if the black plastic nut bottoms out before it squishes the rubber washer enough to get a snug fit. So I picked up a nylon spacer that was about 12mm wide and cut off two 3-5mm sections then installed: Pull out old clips, remove rubber washer. Insert clip in cargo cover hole, then put on the nylon washer, rubber washer and nut. Shove it in and hold while turning the clip handle a few times clockwise to get tension started. Then push down handle to close position to get the rest of the tension. Adjust tension as necessary. Rock solid now. If you follow my lead, take the rubber washer with you to you DYI store to match up the diameter.

Hope this makes sense and a few pics for visual aids.

 

I've also experimented with a "squishier" rubber washer so as to take some of the tension off of the - plastic - screw section with mixed results. Went back to the original setup ultimately.

 

I had some metal washers on mine and has been in place for 4 years. I wound up breaking the plastic clip when i took it off to clean the window. I like the idea of something "squishier" that would tighten it up, but give some margin for overtightening.