A rev limiter removal on an automatic doesn't make sense. Your torque converter is going to select your shift points for you and your engine build will select the redline for you. So, if you have a stock engine, you want a stock redline. It is my understanding that to change the shift points, you get a different torque converter, which will allow higher revs before changing to the next gear. For a speed limiter, an old trick was to remove the overdrive position sensor, but I'm not sure about that working for an automatic or even a modern car, you could try it temporarily (which is useful since you only temporarily go past top speed at a track, airport or strip). Jim Wolf Technologies is a great company that does tune Nissan ECU's. I'm not sure about what they have for your vehicle, but I would surely give them a call. They'll at least point you in the right direction.