in controlling the entry to the vehicle i e for the locking and authorized unlocking of the doors or also a trunk lid to this end a third electrode 60 is provided in a first mounting location on the door handle or on the actuation member for the trunk lid on the exterior of the vehicle the connections and notably the coupling links for the transmission of the data signals are then formed as follows the first coupling link again includes the first capacitive connection 9 between the second electrode 4 of the data carrier 2 and the body of the user 10 via displacement currents 12 within the body of the user 10 the data signals are conducted to the hand of the user 10 the second capacitive connection 11 extends from the hand of the user 10 to the third electrode 60 on the door handle the second coupling link as shown in fig2 includes first of all the third capacitive connection 14 between the first electrode 3 of the data carrier 2 and the ground i e the ground or the pavement on which the vehicle 20 rests the ground is denoted by the reference 16 a fourth capacitive connection 15 exists between the ground 16 and the electrical ground 13 of the vehicle 20 the connection.