This paper deals with the study of wave propagation inside railway vehicle bodies partly made up of composite material and conductive heat-absorbing glazing window panels. Numerical modeling using the full-wave simulation tool Ansys-HFSS is used. The train model and infrastructural items are given as well as the corresponding dielectric constants and conductivities commonly used by the SNCF for numerical studies. The model defined for the railway ground at low frequencies has been extended to higher frequencies such as for GSM or WiFi communication systems. The novel ground model proposed is a layered impedance boundary condition with a layer of 50 cm of Ballast and a layer of ground defined with respect the ITU-R recommendations for electrical parameters and penetration depth. The simulation results for different configurations with relevant materials for the train body and the window panels have shown that in the case of metallic trains, the presence of heat-absorbing glazing instead of conventional glass windows results in difference of around 5 dB for the absorption levels. However, the attenuation is not as strong if parts of the train body are in dielectric especially if the lateral parts are in dielectric.