The skeleton of the body, instead of wood, is made of 2 mm thick stamped sheet steel (‘emboutie’), surrounded on the outside by thin sheet steel as well, while on the inside the padding and cushions are movable; the two front ends close in a frame enclosing the radiator. Lengthways, the bodywork is crossed by an arched profile, a tunnel shape – which seems to divide it into two equal parts – in which the cardan transmission shaft runs. This shaping, which acts almost like a reinforced bridge, contributes to increasing the car’s rigidity and cohesion by lowering its centre of gravity.