The 2006 redesign of Infiniti's largest four-door car transformed it into a capable luxury/sports sedan with a comfortable interior, a choice of V6 or V8 power, and optional all-wheel drive. Ride and handling are good. The M series Infinitis are exceptionally capable, whether cruising on the highway, or hustling along twisty country roads. Further, their interiors are plush and well constructed. This version of the Infiniti was also one of the first cars to offer a lane-departure warning system.