When the cover is extended in place and the vehicle hits a bump or depression in the road the tail end of the cover "flaps" and releases from the attachment. When it happens it is startling and definitely a nuisance. When I next park the vehicle I have to open the tailgate and pull the cover in place again.

Update from Jan 13, 2018: It is now January, 2018 and I have 8400 Km on my vehicle. The dealer has replaced the rear cargo cover at one time with the result that the hold down clips now hold but the cover continued to roll up upon hitting a bump or depression in the road. On a second occasion the dealer replaced the cover with a "NEW" redesigned cover. The only apparent difference is that the cover seems a little stiffer to pull out. However the original problem of the cover rolling up on hitting a bump or dip in the road is still winning the battle. Admitedly the problem has improved slightly but is still occurring regularly. Some months ago I got a short stick and propped up the end of the cover flap. Although being a nuisance (Is this why I purchased a LIncoln?) it does work. Maybe I should get a design job with Lincoln because they certainly don't seem to know what they are doing! Keep up the good job Lincoln!

Update from Dec 17, 2018: Finally, after the installation of three new covers and the replacement of one side panel the problem is fixed. Apparently the problem is in the cover mechanism itself. Wouldn't you think that the designer would actually test these things before actually manufacturing them. Think how convenient that would be to the customer. Oh well, who cares!!! Certainly not Lincoln.