A respective sensing region of at least one radar unit is oriented into a passenger compartment of the motor vehicle and a control device is configured to sense a position of a body part of a person and/or a movement of the body part in the passenger compartment on the basis of the reflection respectively received by the at least one radar unit, thus providing non-contact detection of the body part of the person in the motor vehicle. As viewed from the passenger compartment, the at least one radar unit can be arranged behind a display surface of a display device or alongside the display surface of the display device.