A reader was looking for a replacement remote for a 1998 Infiniti Q45 car that she bought used. She did not have an original remote to reference. We determined that her Q45 sedan does have a factory keyless entry system. The correct remote for 1997, 1998, 1999 and 2000 Q45 cars is a 4-button keyfob with FCC ID KBRASZU07 on the back.
See 1997-2000 Infiniti Q45 remote at this link.
Factory keyless entry systems used on 1997-2000 Q45 sedans are user programmable.