An example relating to the topic of clear visibility is the view of the outside mirror through the side window or potential water retraction occurring on the window wiper. In the thermal wind tunnel, it is possible for examinations to be performed at an earlier stage of development, even on non-camouflaged, non-drivable prototypes – confidentiality is guaranteed at all times. This way, relevant vehicle geometries, such as the A-pillar, water trap and outside mirror housing are accessible for early assessment and optimization.