"if the Beeb were doing a program on car security, would they break into someone's car without their knowledge & drive it away"

Assuming for a moment that you intended that to be a question, and supplying our own question mark at the end of it, I can answer thusly: yes. I've seen it many times. They do a documentary on car security, they show somebody jimmying the door lock open, or fooling the sensor, or whatever. Of course, they don't show it to a reproducible amount of detail, but they show it to make a point of how quick and easy it is for a practiced thief to do - the shock value is what drives the message home to the viewers. "Oh my god, it's that easy for them to do, I'd better beef up my security." I've also seen them demonstrate how pickpockets and conmen work, as well as bank robbers etc etc. Why not? It's a documentary. It's gotta be documented. Otherwise what's the point? It may as well be a work of fiction.