The Infiniti QX4 is a mid-size sport utility vehicle (SUV) introduced in 1996. The QX4 was Infiniti's first entry into the SUV market segment. All model years of the Infiniti QX4 have keyless entry remote fob smart keys that are onboard programmable, which means a person can program the keyless entry remote fob smart key with no special equipment other than the keyless entry remote fob smart key programming instructions. The QX4 was discontinued in 2003.