I have to admit when i lived in NY i would wave to the County police and a few select locals, I feel that we need to have some appreciation for the police, NOT all are A-Holes.
But the ones that take there job seriously do deserve an extra hand or thank you, hey it might make there day and hell one day that officer you waved to someday might actually pull you over one day and remember you by your car and give you a Have a nice day