I wanted Apple CarPlay and the ability to stream music so I ended up purchasing a Sony XAV-AX1000 media receiver, dash kit, wiring harness and antenna adapter from Crutchfield Canada. I used the Metra Axxess ASWC-1 to maintain steering wheel controls. Crutchfield gave me a steep discount on the dash kit, wiring harness and antenna adapter (I think they charged me $5.00 for everything).
The install was painless - the radio bezel came off without any pry tools (I started at the top corners and used my fingers to pull) and removed the 4 screws holding the factory radio. I spliced into 3 wires on the factory harness for the ASWC-1 and I was good to go. I ran the microphone to the driver's side A pillar. I used a fish tape to run the wire behind the A pillar because I didn't want to pinch the wire between the left side of the dash and fuse panel cover. I also used my own grounding source for the Sony stereo, ASWC-1 and parking brake. Its important to connect the blue wire from the antenna adapter to the aftermarket stereo remote wire (also blue) so radio reception is strong. I did not install a backup camera because I really didn't think it was necessary on such a small vehicle, though I presume it too would have been straightforward.
I did have a problem with the radio after reaching half volume as the speakers would start the clip. Initially, I thought I had a defective radio, but as it turned out, the issue was the impedance of the factory Nissan speakers The Sony stereo rated for 4ohm (or 8ohm), however, Nissan commonly uses a 2ohn setup which meant the amplifier in the Sony stereo was working harder than it should be and cutting out.
I just purchased 4 Kenwood KFC01666S 2 way 4 ohm speakers at Crutchfield. They sent the speaker adapters and harnesses for free! I receive them today and will install once they arrive. I have already removed the door panels, which took about 15 minutes to remove all 4 (very easy and straightforward).
I have installed car audio in countless vehicles and the Micra was one of the easiest installs!
Crutchfield is awesome to deal with and their prices and support is hands down second to none. As many have members of the forums have mentioned, the Micra is not sold in the USA, however, from a car audio standpoint, the Micra is identical to the Versa Note.