The Mangusta was the second production road car produced by De Tomaso. Following the Vallelunga debut, Alejandro realized that he would need to use a different business model to find financial stability for his company. This approach consisted of producing homologated road cars in higher volumes. At this point, Alejandro confident with the initial success of the Vallelunga was ready to truly establish himself on the world stage.

The chassis of the Mangusta has a unique origin; a direct descendant of the 1965 Shelby - De Tomaso P70. Following Carroll Shelby's departure from the P70 program, Alejandro became even more driven to prove himself to the world, and notably Shelby. He turned the now legendary designer, Giorgetto Giugiaro, who at the time was working for Ghia. Giugiaro had a design in-hand that was originally prepared for Iso, but they decided not to use the design as they were not seeking a mid-engine configuration. DeTomaso, the shrewd businessman, seized this opportunity and placed Guigiaro's design onto his the 'spine chassis' chassis of the P70/Sport 5000/ De Tomaso - Ghia 1965 show car.

The Mangusta’s aggressive yet reserved design had many signature features outside of the chassis, which included rear engine covers that used a centrally-hinged "gull-wing" opening sequence to provide access to the engine and rear storage compartment. The interior was designed in the spirit of a luxury grand touring car with supple leather seats and many amenities such as air conditioning, electric windows.

The engine was a race-inspired Ford V-8 mated to a ZF 5-speed transaxle with a limited slip differential. The Mangusta was a performer with a fully independent suspension, four-wheel power-assisted disc brakes and cast magnesium wheels produced by Campagnolo.

The name also had origins to the Shelby-De Tomaso P70 as after Shelby left the program, Alejandro was quite upset and determined to show Carroll who was "boss". When asked about the name, Mangusta, Alejandro would often state that the Mangusta (Italian for Mongoose) is the only animal that will take on a Cobra snake and win (referring to Shelby's 'King Cobras').

In 1966, the timeless design of the Mangusta debuted at the Turin Show and took De Tomaso and his Ghia design team to the next level on the world stage. Alejandro was finding his footing.