It's an early step towards more:

Your car has dropped you at work and returned home to avoid CBD parking fees. You then summon it to pick you up and drive you home.

You've arrived back from holiday and summon your car to the airport to pick you and the family up.

You are parking your car(s) in the garage so tightly that you can no longer open the doors while inside.

The car is parked a few blocks away and you want it to come and get you from the restaurant where you've just finished dining.