After taking delivery of my new Tekna 30kWh 6.6kW on 30th December 2015, I went through the same connect and disconnect issues as everyone else, although a reset at the dealer two weeks into ownership removed the greyed out car icon and replaced it with a connected one. None of the You+Nissan or Nissan Connect EV functionality worked however.
This morning, following calls from Nissan Customer Services and my dealer last week, the dealer replaced the TCU.
Neither You+Nissan nor Nissan Connect EV could see the car still, so, through You+Nissan, I first disconnected the services. I tried reconnecting and still You+Nissan and Nissan Connect EV could not see the car.
I next removed the car completely from You+Nissan, then put it back again as a new car. I connected services from the You+Nissan website and immediately You+Nissan could see the car. I then logged into my Nissan Connect EV account, which I had not touched throughout the above changes. Nissan Connect EV worked perfectly, including "Find my Car".
I had to log out of You+Nissan and log back in again to get "Find my Car" to work on You+Nissan but as soon as I logged back in it worked perfectly too.
I emphasise that this was in England and I do not know whether the above will work elsewhere.