Exchange device for data which is partly representative of at least one authorized user of an automotive vehicle

The driver's identity card (14) is entered into an exchange of data unit (12) which has a bistable mechanism able to retain the card in a stable position where a running contactor (38) is operated. The card may be pressed further into the tunnel against spring resistance to operate a contactor (40) producing motor starting or on a second pressure motor stopping after which deactivation of an electromagnet (50) gives card release