People build it and then you can exchange money to receive one, how does that not qualify as a production car? Some are even built in the US (by TMI) and you can find them at dealerships: http://arielatom.com/locate-dealer/ A friend has one and it's perfectly legal to license, register, and drive on the street in some states. It has all the federal auto requirements like indicators, brake lights, etc. and can even pass a e-check (as long as you bought one with a catalytic converter).
Most definitions of a production car require that they are mass produced rather than made to order as well as being an original design rather than an aftermarket mod of a production car. I'm not sure of the exact sales model of the Atom 500, but wikipedia says it was a limited edition with only 25 made. Calling it a production car would be generous.
