The ventilated monocoque upright is a complex hollow structure made of welded chromemolybdenium high grade steel, which provides three times greater strength than conventional materials. This design makes the upright both stronger and lighter than using solid aluminium, thus adding to the unequalled precision of the Koenigsegg suspension system.

The hollow interior allows a stream of air to be drawn through the uprights and brake discs. Fresh air is pushed into the uprights through ducts that are connected to inlets in the body exterior. A series of holes on the face of the uprights enables the air to be drawn directly into the hollow interior of the brake discs, where it is accelerated through the centrifugal motion of the wheel. This provides for a constant stream of cool air to flow through the system, which works excellently to prevent overheating during hard racetrack driving.