Motor vehicle, consisting of a base vehicle, a device superstructure which is arranged on the base vehicle and, if used as intended, protrudes on the bow side beyond the contour of the base vehicle, and a supporting system which is arranged on the bow side of the base vehicle for supporting the motor vehicle when the device superstructure is used as intended, having the features: a) the supporting system comprises a supporting shield which can be pivoted from a transport position into a supporting position, at least one first piston/cylinder unit for pivoting the supporting shield, and at least one supporting arm which is connected pivotably with its first end to the supporting shield and with its second end to the base vehicle, b) the piston rod of the first piston/cylinder unit is connected in an articulated manner to the supporting shield, a supporting shield receiving device or the supporting arm; c) characterized in that that end of the cylinder which is remote from the piston rod is mounted in a rotary bearing which is arranged displaceably in a slotted guide which is situated on the front side of the base vehicle or on a load-bearing frame, connected thereto, of the device superstructure, in such a way that, in the transport position of the supporting shield, the rotary bearing is situated in a position close to the base vehicle and, in the supporting position, is situated in a position which is more remote from the base vehicle and in which the first piston/cylinder unit brings about optimum support of the motor vehicle when the device superstructure is used as intended, and, d) in order to displace the rotary bearing of the first piston/cylinder unit within the slotted guide, a second piston/cylinder unit is provided, the piston rod of which acts on the displaceable rotary bearing and the cylinder housing of which is fastened to the load-bearing frame of the supporting system. a) the supporting system comprises a supporting shield which can be pivoted from a transport position into a supporting position, at least one first piston/cylinder unit for pivoting the supporting shield, and at least one supporting arm which is connected pivotably with its first end to the supporting shield and with its second end to the base vehicle, b) the piston rod of the first piston/cylinder unit is connected in an articulated manner to the supporting shield, a supporting shield receiving device or the supporting arm; c) characterized in that that end of the cylinder which is remote from the piston rod is mounted in a rotary bearing which is arranged displaceably in a slotted guide which is situated on the front side of the base vehicle or on a load-bearing frame, connected thereto, of the device superstructure, in such a way that, in the transport position of the supporting shield, the rotary bearing is situated in a position close to the base vehicle and, in the supporting position, is situated in a position which is more remote from the base vehicle and in which the first piston/cylinder unit brings about optimum support of the motor vehicle when the device superstructure is used as intended, and, d) in order to displace the rotary bearing of the first piston/cylinder unit within the slotted guide, a second piston/cylinder unit is provided, the piston rod of which acts on the displaceable rotary bearing and the cylinder housing of which is fastened to the load-bearing frame of the supporting system.