The Alfa Romeo Spider Series 1 — universally known as the Duetto, though Alfa Romeo used that name only briefly before a trademark dispute ended it — was Pininfarina’s last personal design project before Battista Pininfarina’s death in 1966, and the body he signed off on is one of the few in automotive history that can be described as definitive without overstatement. The round boat tail, the low beltline, the long hood, the simple windscreen — these were not design choices that admitted of alternatives. Rally number 5, a red example photographed on the same Sicilian corner that has already hosted a Giulietta Spider, a Fiat 124, and a Beauford replica, is the car that makes all of those other open two-seaters look like they were working toward something.