MOTOR-VEHICLE REAR SUSPENSION SYSTEM HAVING A MODULAR STRUCTURE WHICH CAN BE CONFIGURED AS A TWIST AXLE SUSPENSION OR AS A RIGID AXLE SUSPENSION

A motor-vehicle rear suspension system comprises a pair of longitudinal arms (10), and a cross-member in the form of a tubular element (90). These components are configured so that the tubular element (90) can be rigidly connected to the longitudinal arms (10) in any of two selectable mounting positions. In a first mounting position, the tubular element (90) is rigidly connected to the longitudinal arms (10) at a position substantially coaxial with the wheel supports (60), so as to define a rigid axle suspension. In a second mounting position, the tubular element (90) is rigidly connected to the longitudinal arms (10) at an intermediate position between the front and rear ends of the longitudinal arms (10), so as to define a twist axle suspension.