McLaren rethinks sidepod design
McLaren have brought quite an interesting update to Spa as they have changed the way to tackle airflow around the top and edges of the sidepod. Previously, the car's sidepod featured a fairly traditional, vertical and solid sidepod panel. Since the Spanish GP, the leading edge of the top of the sidepods featured two or three vertical fins - as on the Lotus - to better manage airflow that will eventually end up streaming over the exhaust outlet.
This time around, McLaren ditched the sidepod panel and fins but instead created a sidepod panel that extends over the side pod's upper side, creating a wing that should help keep the flow attached over the sidepod. It takes no genius to realise that this change will have its effect on the exhaust flow, and therefore also the amount of downforce that is generated at the back of the car.
Also note that the car now also features two small winglets below the mirror. This was inspired by Ferrari's design, except that Ferrari also redesigned its mirror support to act as a winglet. McLaren chose to keep this unaltered and simple add two winglets on each side of the monocoque.