I really don't think that's a risk honestly. I live in one of the roughest districts of Glasgow and leave my bike in my car all the time as my landlord doesn't allow it in my flat. As long as you use your loaf and don't leave it all on display I'm sure it'll be fine.
@Roost353535: He is going real quick. There's been a bit of a history of accusations that his edits have been sped up, I think it's just the way he rides, fast. Looks like a few sarcasm detectors have been turned off here.
Tip 2) drop saddle and don't touch the brakes, ever...
You're welcome.
PS: Would love to ride bikes in the UK if only I wasn't so afraid of having my vehicle smashed open and everything stolen. :/