[aerohead]

These vehicles are dominated by surface friction drag.
Automobiles operate in a fully-turbulent boundary layer,their skin friction is already minimized.
The automobiles drag is dominated by pressure drag which is a function of separation.It is the turbulent boundary layer which allows automobiles to achieve as low a drag as they'll attain.
The premise of aerodynamic streamlining is to reduce or eliminate separation.This is a function of shape.
Virtually all attempts to apply non-automotive streamlining tricks to automobiles have failed.They're a completely different animal.
After reading Song et al's paper I have no confidence that they accomplished anything at all.I believe that their work is extremely flawed.