Motor vehicle system with motor vehicle ignition key and with motor vehicle navigation device, and corresponding method

The device has an interface for receiving movement data (130) e.g. acceleration data and height data, of a motor vehicle user, where the data are detected by a sensor i.e. motor vehicle ignition key (100), carried at body of the user. A calculating device calculates a driving route under consideration of the data. The calculating device proposes a destination place in proximity of or away from a desired destination to the user based on the data so that the user returns to a route to the destination. The device generates a movement profile from the obtained data. The motor vehicle ignition key is provided with a radio frequency identification (RFID) transponder and a LED scale. An independent claim is also included for a navigation method for a motor vehicle.