It was a seminal vehicle for Maserati as the company's first successful attempt at the Gran Turismo market and series production.

[1] In the meantime Maserati's first forays into the grand tourer market, the 1947 A6 1500, 1951 A6G 2000 and 1954 A6G/54, had proven that the business was feasible; but the A6 road cars were still built in just a dozen examples a year—hardly series production.

The main development efforts that led to the 3500 GT were carried out in 1956–57, despite the frantic activity required by Maserati's participation in the Formula 1 world championship.

[2] None were found in Italy, as Italian taxation system and the industry structure forced manufacturers to design every part in-house; a daunting task for small companies like Maserati.

[2] Thus the 3500 GT alongside Italian Weber carburettors and Marelli ignition, used many British-made components such as a Salisbury rear axle, Girling brakes and Alford & Alder suspension parts.

Production of the 3500 GT started in late 1957; eighteen cars were built that year, the first handful leaving the factory before Christmas.

[6] But it was a proposal by Carrozzeria Vignale (designed by Michelotti) shown at the 1959 Salon de l'Auto in Paris that went into production as 3500 GT Spyder.

The Spyder did not feature Touring's Superleggera construction, but rather a steel body with aluminium bonnet, boot lid and optional hard top;[7] it was also built on a 10 cm (3.9 in) shorter wheelbase, and weighed 1,380 kg (3,042 lb).

[9] The body had a lowered roofline and became somewhat longer; minor outward changes appeared as well (new grille, rear lights, radial 185VR16 Pirelli Cinturato tyres, vent windows).