Right now, vehicles whose engines are somehow disabled (out of fuel, out of battery, whatever) just kick you out of their control screen when you ^ on their control seat. This is kind of annoying, especially when you’ve got a multiple-engine vehicle and you’d like to switch to the one that works.
It’s not a huge thing, since you can always just stand next to the control seat and then ^-e on it, but it’s still kind of an annoyance, especially for new players who might not know they can do that.
EDIT:
While we’re on the subject, it’d be handy if pedals automatically disabled themselves when you try to start your vehicle from a seat that doesn’t have the pedals but does have a working engine, instead of getting “you cant reach the pedals!”.