The effects of specific parts inside the vehicle body in a radiated immunity numerical simulation is addressed. The benefits of numerical simulations for electromagnetic compatibility analysis is well known and reported in the literature, nevertheless, the accuracy of the results depends on the mathematical models that is being considered. Numerous simulations were performed, detailing how specific parts of a vehicle can affect the electric field inside a vehicle. The commercial package ANSYS HFSS™ was used due to the extremely fast and accurate simulations since it uses the finite element method technique, which includes hybridizations with the method of moments. This allows full simulations to be performed in a few minutes with controlled convergence, allowing a more extensive investigation. Simulation results are compared with experimental data obtained from experiments performed at Instituto Nacional de Pesquisas Espaciais showing a good agreement.