Speaking as a "civilian", I have been extended a copious amount of grace over the years. Written up for a seatbelt while allegedly doing 73 in a 45 comes to mind....and several "let off with a warning" for various alleged infractions. Obviously, no professional courtesy involved, but not being an A-hole, being polite, being honest ("do you know why I pulled you over? "Probably because I rolled through that stop sign back there...") and looking like a respectable citizen helps.
...waiting for the "Kirk- keep your car clean speech" to roll-in in 3-2-1...