I can't say that the police give my car too much attention. Where I live, in Australia, police officers are more on the lookout for mid-80's to mid-90's Commodores, as they're cheap, fast and as a result, are what almost EVERY young person drives around here. I drive a white '77 280SE, so the police, according to my dad, just think, "Oh, here comes grandpa" and tend not to give it any second looks. I once got waved past a roadside drug test, even though I had a newly-bought bottle of whisky on my seat in plain view, and my P-plates displayed. They pulled the Commodore behind me over.
EDIT: I guess it also helps that I don't drive like the 'typical young person', which means rocket acceleration, dodgy risk-taking, etc. I don't like pushing my car too hard, so my acceleration is typically very slow, and while I do 'take risks' on the road, they're completely within my control and I know for a fact, aren't stupid for the sake of being stupid or impressive. I'm a safe driver, and I only know a few other people my age that are the same.