A passenger compartment has a flat floor, a movable component and a positioning system for positioning the movable component on the floor. The positioning system has a lower rail extending along a first direction attached to the floor, a carriage slidably engaging with the lower rail for sliding along the first direction, and an upper rail extending along a second direction not coinciding with the first direction and slidably engaging with the carriage for sliding along the second direction. An interface member is attached to the upper rail and provided with openings for being removably connected to the movable component and making the movable component integral with the upper rail in a movement along the first and second directions. The lower rail has continuous-track electrical contacts extending along the lower rail. The carriage has sliding electrical contacts arranged in contact with the continuous-track electrical contacts for transmitting electrical signals.