This is not ecomodder-typical, but....
Hoonipigasus aero
Very good explanations of the whys and wherefores of the aerodynamic details, barge board, etc. One thing I noticed, was the rear difusser starts at the driver seat. The first pictures I posted on Ecomodder were of a VW Beetle that had an underfloor that the seat (old EMPI fiberglass rear buckets) was recessed into, but it appears that I still have an account on Imgur, but it's empty.
On the topic of NACA ducts,
he calls out one at 14:32 but it's not, it's more of a nostril. There's no flat rear edge.