Furthermore the Y100 (200mm) slotted element surrounding the crash structure looks to work with this flow and create an airflow structure upstream of it. A pair of tall flush mounted Vertical Floor Strakes can be seen either side of the sloping centre section of the Diffuser  whilst another tall Strake placed further back and skewed in it's orientation is mounted inside these. Two much shorter Strakes are placed outbound and are orientated toward the periphery of the Diffuser. The Strakes purpose is to both align the airflow coming through the Diffuser and create Vortices that will join up with the flow regimes above.
We find a full length perforated Gurney Trim around the periphery of both Diffusers with only the central section changed to suit the aforementioned Y100 changes.