The ones pictured above are not the westafalia tow hitches. I was looking into getting one, but they don't sell them in the US, and you have to import. So i got the one shown in the last picture. With the westafalia hitch, you have to remove the bumper, and insert the hitch into the frame of the car. Compared to the other hitches that mount underneath the car and is bolted into place.
Here is a link to the Westfalia install:
http://forums.tdiclub.com/showthread.php?t=290710
Here is the one I purchased:
http://www.amazon.com/Hidden-Hitch-...5156&sr=1-1&keywords=hidden+trailer+hitch+gti
The hidden hitch works great. No rattling, and it makes it so much easier to tow my bikes.