WHY HAVE I commandeered your attention with this strange and irresistible object? It is obviously not a car. It cannot possibly be real. Does it even have wheels? Is it a submarine?

Sixty years after its introduction at the Paris Auto Show, the futuristic, perfectly Gallic Citroën DS 19 (D series from 1955-75) retains the ability to wow, an atom bomb of style from a time when atom bombs were kind of cool. The DS was the most technically gifted automobile of its time and the most quintessentially modern, in that it scorned...