Tail light lens

No, it is, but, that's just the provision in the main harness, which was the same harness if your car had, or didn't have, BU lights. You need the individual light sockets and maybe wiring and switch up front to make it work. You'll want to either trace that wire up to the driver's side kick panel and beyond, or, to get a good wiring diagram to show you what you might be missing. Is yours a column or floor shift? Auto or manual trans?