McLaren hit a mini target of getting through to Q3 for the first time in its new Honda era in Spain, thanks in part to a new aero package.
The Spanish Grand Prix had been singled out for the next step in McLaren's push towards the front of the grid.
And although some elements of it were refined, the new front wing that appeared gives a clear hint about its development platform going forward.
The new front wing used exclusively by Jenson Button throughout the weekend could be seen as a keystone to its future, with its design revising several key aerodynamic structures.
Perhaps the most important of these changes comes in McLaren's adoption of a more aggressive division of the outer section of the front wing, which will control the way in which the air moves around the front tyre. This will not only provide a direct uplift in performance but also improve how things operate downstream.
As part of this alteration, the inboard footplate section (see yellow markings on both the new and old wing - inset) is slotted all the way back, inline with the flaps. These slots will help to control how this airflow is shaped and are of most importance in yaw.
The endplate was also revised, with a large cutout placed at the rear of its surface (highlighted in yellow). Once again this will change how air moves outboard of the front tyre.
Meanwhile, the vane which is hung from the main cascade has been given a sibling - which is another vane shaped very similarly but obviously it has a further reach.
This new vane will work with its sibling to re-target the airflow's position on the front face of the tyre, before being turned out and around the tyre.
The flaps have also been revised (arrows), with both the penultimate and upper flap featuring slots in their inboard profile, changing the behaviour of the airflow.
This in-turn will have an affect on the Y250 vortex which forms from the juncture of the neutral section and flapped section of the mainplane.
This proved to be an area of intense setup during the practice sessions with both drivers trying out three different configurations, before both drivers finally settled on the new solution.
The openings, which were increased in size for Sochi (inset), were completely cut away for Spain, with the crossover pipework fully exposed to the wheel rim. This changes the way in which the heat is radiated into the wheel, affecting the tyre's bulk temperature, too.
The Vulcan-salute-style brake duct inlet has also been ditched in favour of a more conventional vertical section and separate inlet, changing the entire shape of the duct. This will undoubtedly have an impact on the shape of the tyre wake, too.
Rear Wing & Diffuser
The MP4-31's rear wing has also been treated to some detail changes in an effort to gain some additional downforce. They weren't widesweeping changes, but rather amendments to the mainplane and upper flap profiles to allow for a steeper angle of attack.
The diffuser remains unchanged since Russia, where changes were made to the outer vertical floor strakes (highlighted in green).