The car tested in Jerez (pre session test) was stripped of significant aerodynamic elements like sidepod panels and nose vanes because the team focused solely on improving and checking mechanical reliability instead of pushing for the ultimate time. This changed soon after the first test as wide vertical panels attached on sidepods alongside with lateral flow conditioners and skirts added under the nose where the suspension wishbones meet the chassis.
STR9 lacked any nose vanes on its launch version (studio images), but in Jerez a pair of splitted vanes added just below the suspension wishbones . Nose vanes are common in Formula 1 for more than a decade now, pioneered by Jordan team which preferred to abandon the classic bargeboards in favor of nose hanging skirts. Nowadays multi sectioned vanes consist of two or even three elements and play a significant role on aero efficiency .
Toro Rosso added a pair of fences under the nose cone at Hungary to increase the quality of air passing under the nose and towards the underbody aiming to generate more downforce created by the car body .
The fences under the nose cone , which create an air channel under the car , were revised at Spain having now a more sophisticated shape to improve front aerodynamic efficiency .