In short, the Quattroporte revolutionized the notion of a four-door sedan, and became the flagship of the brand today. To date, six generations of Quattroporte have been produced, proving the vehicle's immense popularity. Maserati first introduced the beast in 1963, incorporating its coupe characteristics and sport style into a machine with four doors. Bodywork was done by Vignale, the results of which were a stunning mix of look-at-me curves. As with its modern day cousins, the Quattroporte was best known for its greenhouse-like windows and protruding front grille with Trident logo.