The bulk update request #10460 has been rejected.
remove alias on_car -> on_vehicle
I think it would be more useful to be specific and use on_car, on_motorcycle, on_tank, on_train etc
Secondly, "on a vehicle" has different connotations and usages for different vehicles. For example, "sitting on a car" strongly implies two things: the car is not moving and the person sitting is not in a position to drive. "Sitting in a car" has neither of those implications. However, someone "sitting on a bicycle/motorcycle/scooter" can operate it, and it can be moving, while "sitting in a bicycle" is a non sequitur since it doesn't have an interior. But then one usually rides "on a train" rather than "in a train", despite it having an interior anyway.