The first generation Infiniti M made its debut as a two door coupe in 1990. It was numbered the M30 and derived its power from a 3.0 Liter V6 engine. The coupe model had no luxuries added at the factory, but dealers offered it with a cell phone and a CD player. It had four automatic gears and its engine was placed in its front. In 1991, a convertible joined the lineup of vehicles being sold under the Infiniti M Series brand name. The other change was that the car had a one-lock system that could be operated from either door. No changes were made to either the coupe or convertible in 1992, and the next year the M series was withdrawn.

In 2003, the second generation M series made its debut. This vehicle was numbered the M45 and it derived its power from a V8 engine. It came as a sedan, but the lack of space was a major issue with the vehicle, as there was not enough legroom for those sitting inside the car to move or stretch their legs. The only change that came in 2004 was that the CD player was moved into the dashboard. The M45 was withdrawn from the Markets in 2004.

The newest Infiniti M series arrived in 2006. It came as a sedan which was available in two versions-entry level and sport which derived their power from a 4.5 Liter V8 engine. The entry level model is equipped with leather seats, power windows, a driver's memory seat that can be adjusted in 10 different ways, and a rear mirror that dims the bright lights of the traffic behind the car. The Sport model gets better tires, HID Headlights and seats that are adjustable according to the temperature.