In the past years aerodynamics of road vehicles have always been considered as a low impact design feature, mainly submitted to style requirements and poorly affecting car performances, if not on extreme sports car. Recently pursuing always greater car fuel efficiency and thanks to always more powerful CFD software and brute computational power things come to an important change: car’s aerodynamic features are more and more studied and updated. The actual state of the art relies on both CFD simulation correlated with experimental Wind tunnel tests. The point is that car aerodynamic wind tunnels offer a very limited description of real word phenomena.