If it's the RE5R05A box, you could grab one from a 2002 Infinity and it'd work (almost, you need to whack the transfer case on it).
I can't see why it wouldn't fit, right up to 2015 models. The gearbox isn't something they've mucked about with a lot until then (except for dropping the 7-speed auto in the STX550, but that has issues too).