Ok, i've looked at it. The mesh has been built rather strangely, and has a few overlapping polygons. Your problem with the back of the cab is your using 3 triangles. 2 large ones and a very thin on down the diaganol middle. This triangle is taking most of the gradient shading of the light so it looks like there is a shading or normal problem.
I have fixed the triangle that do not attach to vertices too. Try and avoid triangles that run past a vertex.
I have emailed you the model back in .x and .b3d format. I couldn't convert it to .3ds at work :o)
I have fixed the triangle that do not attach to vertices too. Try and avoid triangles that run past a vertex.
I have emailed you the model back in .x and .b3d format. I couldn't convert it to .3ds at work :o)