If you press brake and accelerator at the same time for around 20 seconds the car goes into "Exhibition mode" and all drive is inhibited. The normal indication of Park, Drive or Reverse is replaced by a blank square. This is undocumented on the owners manual but once my car hade been trailered to my local dealer it soon became obvious that they knew all about it. To get rid of the mode you need to repeat the process of brake and accelerator together. No real harm done in my case except the inconvenience.
