Hi bud, I have a birdview in my UK zed. It was retrofitted and wouldnt imagine there would be any specific issues for fitting to a JDM.
I am awaiting a replacement at the moment but dont think they fail very ofter, being Nissan the wait is a long one.
Downside of the Birdview, wont accept postcodes, cant update online so you get the info for the year of the disk and live with it.
Its a pretty user friendly unit though although the remote against a touch screen is debatable.
To retrofit they cost about £1800 from the dealer so if you get one with a recent disc it could be worth doing. Other units are available cheaper.