Putting the key into the slot in the dash powers the key via induction. If you separate the metal key from the fob and put the key in the dash it won't do anything. You need the fob electronics to start the car.You can start the volt with just a mechanical key, try it with the batteries out of the fob sometime. Unlock the door, then put the mechanical key into the hidden "mechanical key slot" that your manual describes. .....