One of the things I plan to ask Gary from the A2 windtunnel about, is the importance of flush wheels.
Both the Camaro and the 'Blowfish' Cuda have large wheelwell gaps, yet are .20 / .21 cD
What puzzles me even more, is that there was so much airflow in the wheel well area on that Camaro, that "Moon disks dropped the Cd by 2 to 4 counts ", yet no effort was given / needed to clean up this area around the wheelwell gap.
So you may not even need side skirts.
( It's like everything in aerodynamics comes back with a surprise ! )