A Ford flathead V-8 with unsync'd transmission, powering a totally unbalanced three-wheeled chassis designed to tip over when turned.  Perfect for exploring perfectly flat and straight city streets at 10 MPH.
Later nerdy thought:  The weight efficiency of a Bucky dome is actually LESS necessary on Mars.  Because things weigh about half of Earth weight, you could get away with sloppier and heavier construction using local stones.  Mars has lots of nice rectangular stones laying around, which would be comparatively easier to lift. 
   
    
The current icon shows Polistra using a Personal Equation Machine.