Having already discussed Mercedes use of the U bend in this years diffuser due to the change in regulations regarding the starter motor hole, it may come as no surprise that the team are already making change around the central portion of the diffuser.
Added at this test we see a pair of triangular sections flank the Y100 region (lower inset), their intent to lower the pressure and increase the upwash. In the upper inset we can see the previous configuration, much like their competitors is simply a blunt section that creates a pressure gradient under the crash structure, forcing it upward through both the slot and trailing edge. This of course lowers the pressure behind the crash structure encouraging the diffuser flow to do the same. The addition of the triangulations will lead to the area becoming 'fenced off' as the pressure gradients entwine and create vortices. This is by no means a 'silver bullet' and would be relatively easy to copy by the other teams but as always must be done so with the consideration of many of the surrounding elements that come into play.