The convertible Biturbo was designed and assembled by Zagato in Milan. It was Zagato's first work for Maserati since the A6G/2000 of thirty years earlier. Carrozzeria Embo was first commissioned to develop a four-seater cabriolet version of the Biturbo, but their proposal never made it to production.
The Spyder was built on a 2.4 metres (94 in) wheelbase, some 12 centimetres (4.7 in) shorter than the coupé's. Still, since it is a strict two-seater with folding rear seats, the luggage space is larger than in the original Biturbo. It was on this short chassis that the sporty hardtop Karif was later developed. Overall 3,076 were built over a ten-year period, setting a production record for Maserati Spyders.
The first Spyder was launched at the Turin Motor Show in 1984. It was offered both with the two litre and two-and-a-half litre "export" engine. Two years later fuel injection arrived on the Spyder i. 297 were made in 2.0 L and 122 in 2.5 L form.
In 1989 the Spyder was facelifted as model year 1990, known as Spyder i 1990 (or '90). The car received the full 1988 Gandini treatment, one year after the other models: rounded grille, fuller bumpers, aerodynamic wing mirrors and 15" wheels on five-lug hubs. As on the rest of the Biturbos the export engine grew to displace 2.8 L. A four-speed automatic transmission was available on request.
The third series, or Spyder III, was introduced in 1991 in occasion of Gandini's second facelift that renewed the entire range. This included the new bonnet and grille, ellypsoidal headlights in body-colour housings, a spoiler at the base of the windscreen, deeper body-colour sills and 16" seven-spoke wheels. Spyder IIIs were fitted with Maserati's Ranger limited slip differential Whereas the 2.0 L third series Spyder received 24-valve engines, 2.8 L cars still used 18-valves, thus remaineing the only 2.8 L Biturbo model to never get a 4-valve head upgrade.