[aerohead]

Originally Posted by freebeard

Here's an example:

https://youtu.be/l47hKqnA-lc?t=229

A wickerbill on the diffuser affects the wake (allegedly).

He'd have to flesh out the theory in more depth for it to be of value.
I don't consider anything that has to do with dedicated race cars germane to road vehicle aerodynamics.
Everything he's done has only reduced the efficiency of the car.