Aerodynamics continues to make an increasing contribution to the performance and characteristics of passenger cars, commercial vehicles, motorbikes, bicycles and also in motorsport. Apart from absolute performance and energy use, increasing customer demands with relation to wind noise, soiling, visibility and comfort require aerodynamicists to be involved in many aspects of design, development and testing. These demands together with the necessity to comply with stringent worldwide legislation have seen a significant increase in the volume of wind tunnel testing and computational analyses conducted in recent years.