Emulating the Dymaxion body design is an ambitious project but doable, if you can build a body from scratch. Personally, I'd have to join the naysayers about rear wheel steering though. Turning a corner in town would swing the rear of the car way out to make the front go where you want it to go. Since it is virtually unheard of to do that, vehicles near you would not be expecting it and it would be too easy to hit someone while trying to make a turn.
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