A side panel assembly for a passenger vehicle, includes a B-pillar made of fibre-reinforced plastics material, at least one further pillar made of fibre-reinforced plastics material and following in the rear direction, and a side panel made of fibre-reinforced plastics material and defining a portion of the skin of the passenger vehicle. According to the invention, to make it possible for a side panel assembly of this kind to offer high stiffness for absorbing operating and crash loads while being low-weight, to have a high surface quality, and to be economical to produce with short production times, the B-pillar includes a hollow pillar made of metal as a core element.