I've seen footage from this type of set-up before. Pretty damn cool!

Wondering how they control camera direction though.

Its basically a long piece of aluminium on a swivel mount with a counterweight on the other end.

Did some googling as was curious how they did it when I posted up something similar:

http://www.google.co.uk/imgres?q=gopro+ ... =135&ty=51

Uber cool camera position

The camera makes the track look incredibly narrow. I have a goPro, and I also noticed you don't get a good feel of the changes in elevation. Hills seem to disappear. There's a corner on a stretch of road I frequent that i nicknamed "the Corkscrew", because from where you first enter this series of turns to the bottom, its got to be at least a 100 foot drop in elevation, but on the GoPro video it's hardly noticed.