I have a face lift i think (2000) and just looked to see if i have that lol...i dont. If it doesnt adjust lumbar support i would say its a hook to keep shopping bags upright
Exactly as Warpa says, it is indeed for holding your luggage/shopping bags, and according to the owners manual it has a max load of 10kg. I never thought a little plastic hook could be so useful, but after using mine, i wouldnt be without it (lets me got to sainsburys, get some shopping, and still drag off the line at the lights without me dinner rolling around the back )