The field of vision of the driver during wet road conditions is essential for safety at all times. Additionally, the safe use of the increasing number of sensors integrated in modern cars for autonomous driving and intelligent driver assistant systems has to be ensured even under challenging weather conditions. To fulfil these requirements during the development process of new cars, experimental and numerical investigations of vehicle soiling are performed. This paper presents the surface contamination of self- and foreign-soiling tested in the wind tunnel. For these type of tests, the fluorescence method is state-of-the-art and widely used for visualizing critical areas. In the last years, the importance of parameters like the contact angle have been identified when designing the experimental setup. In addition, new visualization techniques have been introduced. Based on these developments the complete process using the fluorescence method was evaluated and updated to the available technology. Various factors in the experimental setup were identified to improve the reliability and a resulting high repeatability of the experiments between different test sessions is shown. Additionally, new visualization techniques are introduced for enhanced data evaluation which allows an easier identification of possible measures. Due to the increased repeatability, it is now possible to calculate the absolute difference between two analyzed vehicle configurations. For the side mirror glass, the quality of the results is improved by image detection methods. In the end it is shown that these modifications to the process are helpful in evaluating the results of computational fluid dynamics.
