Key

You obviously need the correct key for the car.

But is it possible

Any key would have to be specifically programmed into a car's anti-theft system in order to work. That key would also have to come from the correct blank for that vehicle. It's possible a Vue and Ion use the same blanks, a GM dealer might tell you if so, but a key made for a Vue is not going to start your Ion.

Besides the security system issues there are thousands of keying possibilities for each keyway style. Perhaps one in 1 million might work IF the security system was not an issue.