Studied to achieve a low drag coefficient even in crosswinds, the body featured a lenticular cross-section both viewed from the front and from the side;[5] the underbody was faired-in.

[5] As on the 1900, the engine was an inline-four with double chain-driven overhead camshafts, but used an aluminium block and inserted sleeves instead of the 1900s cast iron one.

[5] Suspension was, as on other Alfa Romeos of the time, by double wishbones at the front and solid axle linked to the chassis by an upper triangle and two lower longitudinal reaction arms.

One was given a fixed roof, becoming an enclosed coupé; the other, doing away with the characteristic bulging wings in favour of more conventional ones, became the so-called "fianchi stretti" (Italian for "narrow hips") spider.

[3] The spider and coupé 2.0-litre prototypes are preserved in the Alfa Romeo Museum in Arese, and are regularly used in classic car races.

[9] The fianchi stretti spider is part of the Schlumpf collection, on display in the Musée national de l’automobile in Mulhouse, France.

[10] A bronze sculpture inspired by the Disco Volante was revealed in the Fiera Milano for the 100 Years of Alfa Romeo in Summer 2010.