Check out the ducts in front of the 993 turbo's front wheels (red arrow)
Air coming into the side inlets of the front airdam gets expelled through these vents, creating a partial seal to prevent crossflow between the front wheels.
I'm wondering if this is applicable to F1 especially post-2005. We could have ducts in the front wing endplates to create the same effect, improving the vacuum below the front wing.
Maybe one of our CFD experts would be interested in verifying this?