This research aims to investigate the external aerodynamics of the IKCO-DENA+ car, which leads to the annoying sound inside the cabin. In this research, the sources of aerodynamic noises were identified using wind tunnel tests on a 2/5 scaled model. Smoke flow visualization of the flow around the car for finding out aerodynamic characteristics and noise sources has been conducted. The results obtained from visualization showed that six different factors can be considered as a source of noises, including 1.the distance between the side mirror and the body, 2. the aerodynamic form of the side mirror, 3. the rear passenger quarter window, 4. the shark antenna, 5. car handles, and 6. indentation design feature on the rear door of the car. Then, within the next steps, the surface modification solutions regarding the identified noise sources were tested. In addition, Measurements using hot wire anemometry and pressure sensors were performed at different velocities of 18, 36, 54, 72, 90, 108 and 118.8 km/h. The results showed that surface modification related to quarter window led to a reduction of the flow disturbances and the aeronoise level on the car’s rear door glass significantly. Furthermore, modifying the side mirror of the car has considerably improved the aerodynamic behavior within the area of the front door glass. Consequently, these two modifications reduced pressure disturbances by 9% and 5%, respectively.