How can the shading errors be fixed, like where the panel gaps are? Its the dark area around that area.
I guess you tried to modifiy the vehicle in Blender. That car IIRC was made in 3ds max, and like some official vehicles uses smoothing groups. Blender doesn't support them, so it doesn't make difference between hard and smooth edges. You have to apply an edge-split modifier in Blender to solve that. Or if you are just trying to edit a part, you can just use multidae, so that the original model doesn't get modified: http://www.beamng.com/threads/10210-Introduction-to-MultiDae
