A wind deflector that is properly installed near the leading edge of the sunroof opening of a vehicle is known to effectively suppress the sunroof buffeting noise. However, the efficiency of wind noise reduction is very sensitive to the position and angle of the deflector. An automatic deflector-traversing device was devised to automate the sunroof deflector test procedure. It can automatically place a deflector at any desired position and angle with high accuracy. The deflector-traversing device was tested in a SUV vehicle at various wind speeds in an acoustically treated wind tunnel. In the test reported in the present work, the investigation area within which the position of the deflector could be varied was approximately $12mm;{ imes};20mm$. Hundreds of deflector positions and angles were tested in the investigation area in a relatively short time period. A post-processing program was then used to process the abundant data obtained from the automatic measurements. For a narrow region of investigation, the post-processing program yielded color maps with high resolution for the high-frequency wind rush noise levels as well as the low-frequency sunroof buffeting noise levels as functions of the positions and angles of the deflector. It is concluded that the deflector-traversing device can be used together with an analytical model for the prediction of the buffeting noise for optimizing the deflector position to effectively suppress both the buffeting noise and the wind rush noise.