I am a bit confused. When I look at the A5/S5 brochure the pictures showing the interior console shows a round start/stop button on the cluster around the gearstick. I have also seen it on some pictures I have seen on this forum. The thing is, my S5 does not have this button. I put my key in the ignition, push the clutch in and then push the key in further to start the car. To stop, I push the key in again and it is then free to remove from the ignition. Is this standard for the UK maybe and other countries have the button ?