This curve is very interesting.
Looks like Haas turned that curve to another level, connecting the airflow from the bargeboards and the sidepod end plates.
The Renault has a different take on the side pod end plate
Maybe this could be a good shape in that area?
McLaren's side pod endplates look like this minus the feathers.
How do these side pod endplates affect air downstream, and are they fed by the barge boards? Do they interact with the rear wheel winglets and by consequence the diffuser gurneys? Do they help fence off the tire wake? Do they guide airflow anywhere else? The flick ups behind the side pod endplates create vortecies as well, do these interact with the floor slots in front of the rear wheels?
Do the rear tires create high pressure on the upper side of the floor?
As the high pressure builds up as the car travels and the spinning tire throws off it's wake directly over the floor, I could see how sending air underneath would speed it up and create downforce. Those tabs and flick ups that look like they scrape the tire are probably increasing the pressure in that area. The centrifugal airflow shed off the rear tire as it spins flows directly on that surface.
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