3D model created in blender and rendered using the cycles engine. The model is ready for subsurf modifiers with unwrapped UVs for every single surface.
Material data embedded in the model with different parts allocated their various materials hence tweaking will be less of a fuss.
Simple interior and undercarriage as usual.
For blender users, apply subsurf modifier level two (shortcut CTRL+2) to get perfect geometry of hood, bumper, doors, panels etc.