Just called Nissan again, they say the BT Dongle just plugs directly into the cable in the armrest cubby hole - don't need a cradle for bluetooth as the phone stays in your pocket.
I really need someone to compare the cable in my pic with theirs.
ther are talking rubbish. You need the cradle to fit the bluetooth adapter to. The old system yes you attached the phone to a specific type of adpator which still slots into the cradle.
Get them to look inside a Z cubby in the armrest and they will see that there is a cradle there. If it a brand new Z, it should also have the bluetooth adaptor already installed into the cradle and this is standard fit now