How do I get the car started and trunk opened when the car has completely shut down?

On my Azera as long as my key fob is near the car the trunk can be opened

Depending on the model you can use the emergency key on your keyfob to open the car.

Which car? Trunk can be opened on most Hyundai's with the car completely shut off and no power by phone and I wanted to seats and pull the trunk release cable.

Call the 800 number