When the Maserati brothers, owners of OSCA (Officine Specializzate Construzioni Automobili), were looking for a partner to build their twin-cam four-cylinder engine in larger quantities, it was fortunate that the mass-production manufacturer Fiat was just considering a new sports car to expand its model range. In 1957, the deal was sealed, and engineer Lampredi put the racing-derived engine through a thorough overhaul to ensure it had the reliability required for mass production. In 1959, the engine was unveiled in the Fiat 1500 sports coupé (later known as the 1500 S). In 1962, the 1500 S became the 1600 S, with an increase in engine capacity to 1'568 cc, coupled with a rise in power to 100 SAE hp. Just two years earlier, the little Fiat had been fitted with front disc brakes, and with all these improvements, the car now reached a top speed of 175 km/h. In 1963, the entire model range was revamped. The 1200 Cabriolet became the 1500 Cabriolet, which now stood out as the entry-level model with 67 hp. The OSCA, whose engine was carried over unchanged, now distinguished itself from the basic model with twin headlights. Despite its timeless styling – which can also be seen in the Peugeot 404 Cabriolet/Coupé, produced until 1968 – the pretty Fiat Cabriolet was destined to be discontinued as early as 1966. Shortly before that, the little sports car had been treated to a five-speed gearbox and a steeper-angled steering wheel (complete with a safety steering column), but its time had already run out. This rare Fiat 1600 S Spider, fitted with an OSCA twin-cam engine, was delivered to Austria and, on 17 June 1966, was issued with an individual type-approval certificate and registered in Graz. As a late-production model, this attractive convertible features the extremely rare 5-speed gearbox – presumably fewer than 300 cars were delivered with this specification. In 1971, the 1600 S passed to a second owner, who handed the car over to his son in 1974. The OSCA remained with him until December 2010, when it was purchased from the seller with just over 24‘000 km on the clock. As a qualified mechanic and bodywork specialist, the seller carried out a complete restoration of the bodywork between 2013 and 2014, which is documented in photographs. The OSCA was repainted in its original color and the body cavities were sealed. All the bodywork rubber seals and the rubber mats in the interior were replaced, and the leather and imitation leather trim were refreshed. The mechanical components were checked and overhauled where necessary – for example, the brake calipers were fitted with new stainless-steel pistons, and the braking system was converted to DOT 5 silicone fluid. The engine was fitted with a new water pump, the carburetors were overhauled, the universal joints and Hardy disc were replaced, the front axle was overhauled, and new shock absorbers and a new fuel tank were fitted. The starter motor and alternator were replaced in 2025. This rare Fiat 1600 S – according to Pininfarina, only 2‘275 convertibles were built between 1962 and 1966 – offers the opportunity to acquire a vehicle with just four previous owners, a complete history, just under 30‘000 km on the clock and in very good condition. The most recent veteran MOT was carried out in July 2026.