The aim of the bachelor thesis was to simulate mud soiling on car doors. The simulations were performed with the PreonLab software, in which the parameters for liquid mud were first established with the help of the cone test, and later used in the simulations on a vehicle. A Herschel-Bulkley viscosity model was used, in which the effects of 4 major parameters were analyzed. The results showed that the viscosity has the highest influence on the soiling, the size of the simulated particle to some extent, while the effect of yield stress can be neglected in vehicle simulations.