Abstract: Strong crosswinds pose a severe threat to the safety of vehicles driving at high speeds. In this study, the crosswind sensitivity of a three-box sedan is investigated using a coupled aerodynamics-multibody dynamics simulation approach, with the vehicle’s lateral displacement serving as the primary evaluation index. The reliability of the numerical simulation method is validated by wind tunnel tests and on-road crosswind tests. On this basis, the aerodynamic characteristics of the vehicle under crosswind, the correlation between aerodynamic parameters and crosswind sensitivity, and the influence of different crosswind conditions on vehicle crosswind sensitivity are analyzed. The results show that moving forward the vehicle’s center of mass is effective in mitigating its crosswind sensitivity; however, its effectiveness gradually diminishes as the center of mass moves further forward. Among the aerodynamic parameters, the yaw moment exerts the most prominent effect on the lateral displacement, followed by the lateral force and lift force. Moreover, the yaw moment is identified as the dominant factor governing the lateral displacement acceleration, yaw angle, and yaw angular velocity. Additionally, lateral displacement is found to be significantly more sensitive to vehicle speed than to crosswind speed. Specifically, the crosswind speed exhibits a quadratic correlation with the lateral displacement, whereas the lateral displacement is a linear function of the vehicle speed. For instance, when the vehicle speed increases from 100 km/h to 160 km/h, the lateral displacement increases by 0.96 m.