That's the one. I did notice four screw holes in the top of the hatch (on the inside, near where the struts attach) that are painted over. I wonder if that's where it attaches.

I'll call the dealer this afternoon and see what they say. Thanks for the tip about it being dealer-installed--that makes sense. When we bought our GL, if had JUST arrived at the dealer (in the middle of a bad winter storm) with only a few miles on the odo. They probably did a pretty hasty inspection to get it ready for delivery.