Hands-free system to unlock and/or to open a motor vehicle opening

System for unlocking and/or opening a vehicle body panel (C) of a motor vehicle comprising a management unit (2), transmission/reception means (3) connected to said management unit (2), a transponder (4) carried by the user, the transmission/reception means (3) of the vehicle comprising at least one antenna (5a, 5b) located on the body panel (C) or in the vicinity thereof, said transmission/reception means (3) communicating with the transponder (4) only when the latter is situated in the immediate vicinity of said antenna (5a, 5b), the management unit controlling the unlocking and/or opening of the body panel (C) when the transponder (4) is presented according to a predetermined sequence to the antenna or antennas (5a, 5b) of the transmission/reception means (3) of the vehicle.