Extreme Dimensions Door Caps The Infiniti Q45 is a full-size luxury car that served as the flagship of Nissan's Infiniti marque from 1990 until 2006, when the Q45 was no longer exported. It is a rear wheel drive sedan powered by a V8 engine. The original Infiniti Q45 was based on the Japanese-market Nissan President (?? ??????), the flagship sedan of Nissan, but later generations were based on the slightly smaller Nissan Cima (?? ???). The Q45 competed most directly with the Lexus LS and Acura Legend, as well as the higher-priced BMW 7 Series, and Mercedes-Benz S-Class.