"[3] Segre began working at his father's construction business, only to have his career and education interrupted by the outbreak of World War II.

When allied troops arrived, he made himself available to the US command, and after a brief training in Tunisia, parachuting into the Canavese, he became an official liaison between the Office of Strategic Services (OSS) – precursor to the modern CIA – and partisan groups working in the Piedmont.

[4] Following positive recommendations from the Allied Command in the immediate post-war period, Segre was hired as a manager at Ford, graduated in engineering[4] and subsequently moving to Siata (Società Italiana Auto Trasformazioni Accessori) where he studied automotive design with Giorgio Ambrosini.

In a brief racing career, Segre took 1949 and 1950 first place victories in the Mille Miglia Turismo 1100 class (in a Fiat 1100)[4] – with teammate Gino Valenzano (1920–2011).

Luigi Segre died suddenly and unexpectedly in a Turin clinic at age 43, during convalescence after successful removal of kidney stones.

Doctors suspected Segre had contracted a viral infection during a recent business trip to Brazil, but at the time the hypothesis could not be confirmed.

[4] Eventually, English-speaking Segre would travel to the United States to meet Chrysler's chief stylist Virgil Exner and CEO K. T.

Segre and Karmann encountered each other at international automobile shows, and after an initial discussion prompted by Wilhelm Karmann, Segre secretly began working, obtaining a Volkswagen Beetle to use as a basis for a prototype[10][2] – The Type I's were difficult to come by and Gian Paolo, Mario Boano's son, purchased one in Paris and drove it back to Turin.

The styling of the Karmann Ghia integrated work by Segre as well as Mario Boano, Sergio Coggiola and Giovanni Savonuzzi – and at various times they each took credit for the design.

[13] Furthermore, the design bore striking styling similarities to Virgil Exner's Chrysler d'Elegance and K-310 concepts, which Ghia had been tasked with prototyping – and which in turn reflected numerous cues and themes developed previously by Mario Boano.