My 370z got frozen

Originally Posted by ChrisSlicks

The only way to get in will be to restore some electrical power by tapping into a live 12V (direct battery) connection.

The easiest access is probably going to be from under the car, i.e. jacking the car up, jack stands and removing the engine splash guard. You should have access to the starter motor battery connection and pretty much anything else can be used as a ground. A battery jump box or battery charger will be the best bet. Once you get the door and hood open you can do a normal top side battery connection to re-charge or jump (negative still goes to chassis, not battery).

Also an uncut key is not acceptable. Was the dealer ordering keys or did they lose the original? If they can't get a pre-cut key from Nissan then you should demand a new driver's side door lock and key. If you car is new I would also demand a new battery as this one has had it's life shortened by being drained completely, presumably from sitting around at the dealer.