The knob is on the right because the buttons remained in exactly the same position as the Mark 1. There were reasons for this, at the time. It is unlikely that we'll want to change the fascia anytime soon - the tooling was very expensive.

In any case, it could be argued that it is advantageous to have the knob on the right in left hand drive cars. It is usually more important to be able to see the screen clearly while operating the menus and other button functions than while turning the knob.

Rob