In this paper a test method for measuring the car aerodynamic noise in the Fiat wind tunnel is reported. Through this method measurements of vehicle interior noise in the test section generated by air flow are performed. The separation between interior aerodynamic noise and background noise (fan noise, self generated noise in the tunnel, etc.) is performed by simulation of the last one with loudspeakers without air flow. The present method allows also to separate the shape noise contribution from aspiration wind noise and to localize the most critical acoustical areas into the car. By means of this method it is possible to optimize the car shapes and seals in order to improve the vehicle acoustical comfort.