A semi truck Full model and It has fully its own materials. I have included here with some Dielectric and metallic node groups in blender file. Thanks to these node Groups that we can adjust the reflectivity its color color of main truck body the metallic character and all the stuff like that. And also the main file is a blender file which is a free open source software so you don't have to worry about how to deal with it and if have this software or not its very easy to open and handle. Thanks.