I've read this question a few times over in the last day or two and to be honest, I have no idea what you want! I would like to help but am a bit confused by the term proper framing! Mahogany looks nice! Can you give me any more info? Like 'mechanically driven' Is it clockwork? I suppose the main thing to take into account is simplicity! Leave out the things that are not important. They will only clutter the model! The scale is important too! If it is too small, it will be hard to see! Do you need to make the whole car or could you just make a section of the relevant parts! ie. If you are designing a new drive train, is the paneling of the car needed! If the people you are presenting this to have knowledge of cars, then they will not need to know that the doors open and close!
Give us an idea what you are after and lets see what we can come up with!
The key to success is information not eye candy!
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“It's kind of fun to do the impossible.” Walt Disney