I'm actually in the UK and it appears until relatively recently, the CAA did assert control over indoor airspace. But recently they've relaxed the rules and said if there's no possiblity of escape, you can do what you want.
That does mean technically that if you're flying a drone indoors, the legality depends on how wide you open the windows.
As for airborne ground vehicles - it's difficult to imagine a situation where it would legitimately be a concern, which is why it's a grey area :)