My car is the same.
Watch me blame it on shoddy quality and get a new tranny out of it

I mean i would take it in and have them dig around and try and see what's wrong but more problems will probably occur if those clown dealer heads start touching things. It's goes threw the gears perfectly it just isn't smooth going to a stop. Plus once and a while when the car sits for days , I take it down the back roads and when it's around 3-4,000rpm my middle rpm gage moves up like a rev for a second or two. What could possibly going wrong. I need to have this takin care if before car is out of warranty

Power take off. A term for the gear(generally 1st) you only use to get the vehicle rolling.

With the way other people around where I commute drive, it's hard for me to drive the Z the way it's designed to be driven. People here start applying their brakes 1/4 mi from a light with only a few cars in between. It's aggravating. The main reason is that I drive a standard and don't like having to creep the car anywhere. And the inching forward at red lights kills me.
Sorry, back on point: I generally don't believe the Z was designed to hit 5mph or less for long rolls. Nissan does their AT well in other cars. This one just has a higher gear ratio for supporting harder acceleration. With moderate braking, you can stop the Z very smoothly. I just had to re-learn how to gauge how 10 other cars are going to stop to avoid being right up on one while they unnecessarily rub off their brake pads. This gives me a little more room to brake a little harder than gentle when stopping behind them.