possible idea for areo wheel covers/skirts..
 

this is so odd looking, it's called "floater wheels" there like spinners but weighted so it looks like the car is floating when they drive away.. could make for some decent ideas for front wheel covers?
YouTube - 26 FLOATERS

Why would these be preferable to regular wheel covers? Are you suggesting they be not round?

I guess by not spinning they'd be less likely to induce a vortex in the passing air. Maybe some sort of fins or spoilers could even be added to guide the air and keep it moving smoothly onto the body after the wheel cutout.

ETA: I wonder if the covers' bearing drag would cause a greater fuel loss.

What about mounting your full panel to them. Design the panel so it could turn in to the wheel well. Kinda like the wheel is holding a shield. I think Cadillac designed a car at one point that the panels turned from side to side when you turned the wheel.

Those are truly bizarre looking.

One disadvantage of mounting an aero panel directly to the wheel though is you'd be increasing unsprung weight (and it would impart road shock/vibration directly to the panel/structure).

Also, you need to consider that the wheel moves up & down as well as angling left/right.

But ... wow. So strange looking. Reminds me of a car sliding on ice with all 4 locked up. :)

I'd love to see an aero comparison between a rotating flat disc and a stationary/floating flat disc. My guess is the difference between the two is negligible. :o