Empty spot in trunk

In the trunk, in the spare tire area, there is a molded plastic recepticle for the tow hook and then a molded plastic recepticle for something else. What is supposed to be there?

It could be for the thing that unlocks the locking wheel nuts. I got a flat last week for the first time since i got the car and was stunned at how tight the wheel nuts were. I used a spider and lots of leverage. If this had happened in the dark or rain with only the jag whealbrace id still be there!!!:2cents: