In the past, the external shape of cars has evolved particularly for safety reasons, comfort improvement and also aesthetic
considerations. Consequences of these guidelines on car aerodynamics were not of major concern for many years. However, this
situation changed in the 70’s with the emergence of the oil crisis. The first studies on the overtaking effects were investigated in
response of the weight reduction of cars involved by the first oil crisis [1]. After this oil crisis, car manufacturers have made
substantial efforts to reduce the fuel consumption.