I'm 31 years old, and in my lifetime have never had a positive, direct experience with the Police. Ever.
I grew up in the suburbs in Oregon before moving to Australia, and grew up living under a completely corrupt police force- it was proved in court that the police force regularly pulled over attractive females (sometimes outside their jurisdiction) on bogus charges, and offered an "out" from the ticket/charge in exchange for sexual acts. They took bribes, planted evidence, and threatened those who tried to stand up against them. My own Mother was abused by her second husband, and it took the police over an hour to make to our house. Why? We proved that the nearest officers were asleep in their car.
I know rationally and intellectually that the vast majority of police are dedicated to public safety and protection, but the sight of a police car (or suspected undercover car) skyrockets my blood pressure, makes my palms sweaty. I often have to pull over and do a few deep breaths.
Although police cars in Australia are not exactly like the UC cars in the States, it's good to see a guide like this.