[SketchySeaBeast]

Couldn't the driver just authenticate as a passenger? It's not a good assumption to assume that, because there's only one cell phone in the car, it's going to be the drivers, so I don't know know an approach where the driver just can't circumvent the restriction.

[hector_vasquez]

The car would need to authenticate the driver as the driver, and each passenger as a passenger. Plenty of ways to do it. As an iPhone user, TouchID and FaceID come to mind.

[SketchySeaBeast]

That could be an option, I suppose. Not looking forward to the day I can't drive my rental car because I own an Android.