I've just moved house, and there's lots of free parking on the street outside. I have no issue at all with people parking, as of course they're entitled to do. But there's one woman who repeatedly parks up for about 10 or 20 minutes, leaving her car engine running. I'm not sure what she's waiting for - there's a school right next to us, but it's not school pick-up time.
It's rude, right?
I am too British to say anything. What are your best tactics for signalling my irritation?