I think a vehicle is a kind of container, so the existing code works.
This seems to bring that back:
Understand "stand on [something]" as standing on.
Standing on is an action applying to one thing.
Carry out standing on:
try entering the noun.
It seems a bit strange that to stand on a container would enter it, but I guess it would depend on what’s in the game (a boat? a lake?)
I suppose this all demonstrates your earlier point…