This sounds legit to me. I agree, just be polite and respectful if you have to deal with a LEO. 99% of the time they will be polite and respectful back. If you are a dick, most will continue to be professional but you're certainly increasing your odds that your rudeness will bite you in the ass. A warning may turn into a ticket, a ticket may turn into another for a cracked windshield, bald tires or for littering for throwing the first ticket on the ground. Don't get worked up. Why risk escalating it? Why not give LEO's the same common courtesy you give everyone else?

My father who is a veteran of the AZ Highway Patrol has always told me to never allow a search of my car.

Another standard questions is "have you had anything to drink today?" Even if you just had that one beer an hour ago while watching the game, don't say "Yes." While you might not be anywhere close to drunk, you saying "yes" means you're going to end up doing a road-side even if you explain you only had "one beer." Every single piss-drunk driver on the planet says they "only had one." To a police officer "I only had one" means it's time to make you walk the line to be sure...as they should. Drunk drivers suck. If you truly had more than "just one", don't drive in the first place.