The Citroen 2CV was a wonderful example of a radical but honest approach to car design - as it's rarely seen anymore, if ever. This 3d-printable design is not an attempt to recreate that car; it's simply my interpretation of design elements shown in various versions of it, notably, the 1939 prototype shown in one of the images above.  So I know, a real car usually has at least a front window. But the single headlight really was in those first 2CV prototypes, for cost- and weight reduction purposes.  
The car is printed on its side to enable the 'captured' wheels to rotate, without assembly (not sure who invented that approach, but big thanks!).  The default size is roughly scale 1:30 compared to a real car. That's a nice size, but it can take a bit long to print. I've successfully printed versions at 70% and 50%, they turn out very cute too.  
A heads up: depending on what I end up doing with it commercially, this model may only be available temporarily - so best to grab it while you can.