Due to the regulations banning beam wings for 2014, designers have searched and are still searching for any possible way to recoup some of the lost rear down force.
I think that Mclaren designers have ingeniously come up with a "fake" suspension part that does not move AT ALL. On each side of the gearbox there is a rigid peice of carbon fibre construction cantilevered to the suspension uprights. Each cantilever acts as the mounting point for the real tie-rod (or tracking rods) for the rear upright.
This gives a broad Immovable, rigid and hence legal surface to mount the rear wing and form a replacement beam wing. It is legal as it is not considered body work but a suspension part.(??) I may be wrong though hahaha.
What do you guys think?