The common way to determine a vehicle's crosswind sensitivity is by measuring a model in a wind tunnel or by driving a prototype past a crosswind facility. This happens usually at a late stage of the product development process because hardware resources and knowledge about the future production vehicle is needed. In order to gain reliable information about the aerodynamics of a vehicle early in the product development process, Computational Fluid Dynamics (CFD) is used to collect data. Until now it was not possible to make precise predictions on the aerodynamics and flow conditions for driving under the influence of crosswind. This paper presents approaches and suggestions on solving this shortcoming. The introduction outlines the problem concerning crosswind and gives background information about the present work done in this field. Further the experimental vehicle is presented. Next the first CFD simulations are compared to wind tunnel measurements to ensure the accuracy of the calculations. Therefore, a setting like in the wind tunnel with steady boundary conditions is chosen. To investigate possible causes for crosswind sensitivity the fluctuations in the flow field are analysed by means of statistics. Examinations of their power spectrum reveal how their power is distributed over frequency. Further, CFD calculations with transient boundary conditions are presented. They confirm the influence of the discovered fluctuations for unsteady oncoming on the driver. In the presented approach two aerodynamic settings are introduced: an A2 with tear-off edges applied on its taillights and one version without. Transient calculations with these two variants are conducted to search for fluctuations that cause different yaw reactions on the two. With the use of statistics differences in the standard deviation of pressure are found, which result from the modification directly. The examination of the power spectrum of pressure in these areas exposed the energy induced by fluctuations that changes with the yaw angle. These variations take place in a frequency band, which impacts vehicle dynamics. The numeric simulations with transient boundary conditions affirm this result: the additional yaw moment caused by the small aerodynamic modification will influence the driver's behaviour. The significant difference in yaw moment can only be observed on an oncoming flow with time dependent changes in direction. Future investigations need to show whether another property of the A2 might carry weight: the yaw eigenfrequency falls into the same frequency range within which the driver intensifies the response to crosswind excitation. With growing velocity magnitude it approaches 1.2 Hz.