on both of my armadas and my qx, the first mod i did would be to remove the resonator and factory muff and replace with a magnaflow. that would let the car breathe a little better and let the V8 be a V8.. the exhaust tone sounds really good with the resonator removed.
I did the same on both previous cars as well. On my Armada I had a magnaflow and some Cajun b pipes whilst on my G35 there was way too much. Both were loud so I was tempted to keep the qx80 quiet but after hearing some other Patrols / qx80 with the vk56 engine and the valvetronic muffler I'm hooked
Finally got it installed two nights ago and it sounds awesome when the exhaust is open. When it's closed it sounds very close to stock.
I had muffler tips installed as well.
Weirdly I noticed that when the exhaust is open and warm after a drive, it seems to trigger the rear corner parking sensor when I'm backing up into my garage.
I don't know if the parking sensor is going bad or maybe the hot exhaust fumes are bouncing off the garage wall and triggering the sensor particularly because the exhaust is now throwing air straight out the rear instead of down to the ground.