keef is right. '97-'01 Infinti Q45. Indeed, it was called the Q45 since it debuted in 1991, despite the fact that from '97 to '01 it actually used a 4.1-liter engine. That marks one of only two times Infiniti ever lied about the engine size in the badge number, the other being the QX4 from 1997 to 2004 - from 1997 to 2001 the vehicle used a 3.3-liter V6, and from '02 to '04 it used a 3.5, but it was called the QX4 until the 5.6-liter V8 took over in 2005 and it was renamed QX56.