You want something like the one in the bottom picture right?
http://www.vwgolfcountry.net/blog/ Couldn't find any pics or sketches that give more detail.
Or what about safari style where you put it on a roof rack? Mess up the airflow big time and probably would be noisy.
Custom make one that mounts off your rear bumper? Have a hitch? Make a carrier that fits in the receiver?
That said, I'm impressed how comfy I am in such a tiny car.
X2, after a 520 mile road trip with four passengers I had to get re-used to having the seat all the way back. The interior shape/positioning is perfect, I drove a jetta 4 for 350 miles and could hardly stand the cramped knee room and cheesy seats.
This is all off-topic, but I guess that's okay since it's my thread. My '03 Golf is not bad, but I do admit that I somehow magically feel more comfortable in the '82 Rabbit. I was in a friend's '98 or so Jetta back when they were new and I felt like I was kissing my knees even with the passenger seat back all the way.
The seats in my Rabbit are pretty comfy, I'll admit, but I think I'm gonna swap in something better down the line. I really like the seats that came in Volvo 240s (or even 850s). Very orthopedic.