A bunch of images in this PDF below, not really "wind tunnel" related but dealing with aerodynamics just the same.
What this 2011 paper did was make me aware of another side of automated self-driving cars, not so much fitting more on the road to ease traffic, but the aerodynamic advantages of drafting. It is very convincing, at least it was for me. Three vehicles bumper to bumper 6-7% reduction in fuel consumption. Not earth shattering, but an improvement.
https://gcep.stanford.edu/pdfs/ChEHe...0_11_trans.pdf
Unrelated:
http://www.theoildrum.com/node/5912