[aerohead]

It would be nice if Peugeot discusses the technology.
As I understand it,on a shark,it's skin sequesters pockets of dead water between all the dendrites,and water flowing over the skin flows over as much 'water' as skin,reducing surface friction drag.Penguin feathers trap air bubbles.
On a car,the entire surface is already coated with dead air,and airflow never actually touches the cars surface.
The turbulent boundary layer would be quite mature by the time it reached the shark skin.
I'd suspect that if the shark skin lowers drag,then it's doing it as micro-VGs,amplifying the kinetic energy mixed in to thwart separation.