You would need to render each part of the wireframe from the exact side, front, back or top (zero degrees field of view). You would then use the map info files (to be found in the CMX Viewer files) to resize and position the rendered frames. Of course for rendering the front you would have to leave out everything that does not belong to the front.
I'm not familiar with 3D editing or rendering, only skinning but I think that alone finding out which polygon of a bumper is mapped from the front and which from the side unless you want to use the MSz kits as a reference.
I don't know if you can render a scene with a transparent background so you'd get a transparent .png or whatever format to work with. If that is not possible render it on a black background, then in your image editing program choose the layer option "multiply negative".
I don't really know why you would want to do this or how much you know about the programs you would have to use so I'm not sure if this post is of any help.