I have to disagree about the cops "just doing their job" and "if your not doing anything wrong they won't mess with you". I think jealousy is a massive issue with many Police (not all), if you have something they don't or are doing something they can't (for example their wife or job won't let them) it's amazing how many Cops will then try to wreck your enjoyment.
That has rang true my whole life having had many toys, one of the best examples was with one of my cars. I started a Tool & Die apprenticeship right out of High School which set me on the fast track to earning great money at a young age, when I was 20 I bought a 2 year old customized Corvette that was a real head turner (but 100% street legal). I quickly found out that getting pulled over was going to be a regular occurance - in the first several years I was pulled over in excess of 25 times for everything imaginable. Ironically I only recieved 1 ticket which was for speeding, that was a speed trap that was set-up out in the country (speed limit reduction sign hidden by an overgrown tree - ticket later dropped).
I got to the point with that car that when ever I saw a Cop I would intentionally turn and go a different way if at all possible. I was taking my girlfriend home late at night and saw a cop sitting on a side road watching traffic, I told my girlfriend I was going to go a different way because if I continued straight I figured I would get pulled over, she didn't believe me so I continued on to prove it to her. Sure enough I got pulled over, I provided registration and proof of insurance, then the cop started looking over my car trying to find a violation. After finding nothing to write me a ticket for he sends me on my way saying that he pulled me over "because I looked like a suspicious vehicle" (as I was traveling the speed limit on the most heavily driven multi-lane road in that section of the city).
I have what seems like endless amounts of Jet-Ski, ATV, Snowmobile, Motorcycle, Car, & Truck stories like that. I've only had a few tickets ever in my 42 years, but those have all been dropped by simply paying the Police more money - ironic how that works.