Agree with mikey.
And I've never been pulled, bar the time I was lost in leicester and the officer just helped me out. As stated it depends on the driver and the cars visual appearance.
The police haven't done anything wrong in my eyes, sitting in a car park and blipping the exhaust every 5 seconds is known as disturbing the peace so it's inevitable that they'll do something
(I'm not stating that you've done this but someone always does it) There are too many prats on the road in all fairness.