An alternative to wheel covers?
 

Called brake dust shields, branded Kleen Wheels, what's your opinion on any aero benefits? What if their vents were closed?

https://www.kleenwheels.com/componen...015/task,view/

I get that if a particular style of wheel was especially resistant to airflow crossing its surface, like maybe it sticks out real far, or was especially bad at creating turbulunce, like maybe it's shaped like a fan or is spoked, that covering it with a smooth mooncap with a perfectly radiused surface would offer substantial benefits but so long as the wheel doesn't stick out and isn't particularly convoluted, I think the airflow through the wheel is the primary problem, with turbulence within the wheelwell secondary to that, both of which I think the brake dust shields would control and if possibly modified to block air might be even better.

Seeking educated opinions

I searched for them on here and skimmed through the first ten results. People seem to think that it would help, but not as much, because they are on the inside of the wheel.

kleenwheels
 

An aspirated void cannot support airflow.As soon as airflow encounters a void it must turn into the void,disrupting the flow and initiating turbulence.
If you can completely seal all the wheel openings,like Ford's ATLAS concept pickup active wheel shutters,then the air is sequestered inside there,creating a pool of stagnant air of which the surrounding flow can skip off of,like a birdbath spoiler on an old MUSTANG GT of the 80s.
The active shutter addresses brake cooling.Smart thinking.

Apparently manufactured through single-piece construction using aircraft grade aluminum and painted in matte black.

EDITS: as much as $130 for four.

And... the Ford Atlas concept auto shuttered wheels aerohead mentioned, showing open and closed position:

http://www.sae.org/dlymagazineimages...1731_15535.jpg

Honestly, they could have the shutters open during braking, when aerodynamics work against you, and it would mitigate some of the heat.

http://www.fordf150.net/atlas-concept/

I thought it would be a passive mechanism based on rotation, but apparently there are batteries involved.