I got the opportunity to finish blanking the holes on my 2007 BMW MINI seven hole rims. The mod creates a "flat" surface to improve aerodynamics. Preventing the airflow from flowing THROUGH the rim face should prevent much of the turbulence created by wheels. I don't use my brakes enough to worry about excessive heat and fade. Rear wheels were done two or three months ago some more details are available earlier in this thread.
Here is some of the data behind the thought (citation for the article this comes from is linked below):
Here is the look:
CITATIONS:
"AEROHEAD" opinion cite... somewhere on ecomodder.com I swear it.
Alexey Vdovin, "Investigation of Aerodynamic Resistance of Rotating Wheels on Passenger Cars," (Gothenburg, Sweden: Department of Applied Mechanics, CHALMERS UNIVERSITY OF TECHNOLOGY, 2013).
http://publications.lib.chalmers.se/...302/176302.pdf
See also:
http://publications.lib.chalmers.se/...ext/133661.pdf
"Blocking the crossflow through the rims result in increased static pressure in the front wheel house and thereby an increase in lift, whereas blocking the crossflow in the rear result in increased downforce due to an increased flow rate through the diffuser. It was however shown that the resulting flow around the rear wheel was highly dependent of the rim design in the front."