Pininfarina died just a month after the Duetto's introduction in March, 1966, so the model carries the distinction of being his last design. Its design is virtually perfect in concept: an aerodynamic profile with a dramatic blood trough down the sides that ties the symmetrical front and rear together.
The Duetto, whose side concavity appeared later in muted form on the Daytona Ferrari, comes very close to being a streetable show car. Its rarity is indisputable: the car was produced for only two years. The 1968-'71 spider, with almost identical bodywork but with a 1779 cc engine, is properly called a 1750 Spider Veloce.
The Duetto's 4-wheel disc brakes, twin cams, five-speed gearbox and an all-alloy 1600cc engine were significantly ahead of the market in '66. It comes very close to being the ideal minimalist sport car, with only enough creature comforts (such as a water-tight top) to make it usable in all climates. The Duetto's dash is unashamedly metal, and all controls operate with a directness that is often lost in modern sport cars. It is the least tricked-out of the series of Alfa spiders that continued with only detail modifications until December 1994.
While the interior of the car is roomy and very comfortable, the driver must cope with the straight-arm, bent-knee posture that is characteristic of most Alfa Spiders. For this minor annoyance, Duetto owners command one of the most robust powertrains Alfa ever produced. The Giulia engine has wet sleeves, making all wearing parts replaceable. Unfettered by significant emission controls, it offers a level of performance (and ease of maintenance) lacking in the later and larger-engined models.
Problem areas to look for when buying a Duetto center on damage to the fragile front and rear sheetmetal and rust, primarily around the rear fender arches and beneath the rocker panels. If there's any rust on the floor pan, inspect the area where the front end of the rear axle trailing arm attaches to the body. As with any Alfa, check the radiator cap and dipstick for signs of water/oil emulsion, which looks like chocolate malt and indicates a blown head gasket.
Advertised asking prices for Duettos range from $3,000 for project cars to $25,000 for concours-level restorations with mirrored undersides. Unless you enjoy the restoration process, buying anything but a rust-free, proper car is a financial mistake. Many Duettos have been fitted with later 1750cc engines; this makes them slightly more driveable but over time will detract from their collectible value. For $10,000, you should be able to buy a decent car in good running condition with no major flaws.
The Duetto has achieved cult-car status. Unusual for a collectible car, they can be used hard, even for everyday transportation, as long as you're willing to care for the delicate front and rear bumpers by parking wisely.>