Well from what I could see it it mounts flat to the fire wall. The pedal assembly slides back and forth on a rod. I think (I can't tell for sure because I didn't stick my head under the dash) the point where the pedals connect does not change. It seems that the hinge(?) point stays exactly the same. So the master cyclinder does not move. It stays in place.
It is definately something we may want to look into. The guy who did it said he could not believe how easy it was to do!
A lot of cars will go to this because of the liability caused by the instalation of airbags. For an airbag to work properly, you have to be a certain distance from the steering wheel so that the airbag can fully inflate before you hit the bag. If you sit to close to the wheel, because your height impared, or long leg impared. Your sitting to close to the wheel. When the airbag inflates it hits you at 200MPH and causes more injury than it prevents. As long as the airbags are installed you will see more and more cars being built with adjustable pedals.
Airliners have this same kind of system. We want to sit at a position that is optimal for seeing out of the cockpit. Were supposed to be looking for other aircraft. So we have a target in the cockpit that you position your seat with and then adjust the pedals to your liking.