No...that kind of stuff makes you look like a liability to your department...something they frown upon (to put it lightly). If you take action off duty, they are responsible for you...if you do something bad, they're taking the hit. I've specifically been told, unless some really bad stuff is going down, just ignore it...or if you really feel compelled to do something, call it in and let the uniform guys go and take care of it. Any type of violent crime, you should take action, but any minor stuff....and especially vehicle and traffic law violations, you're expected to ignore. Superior officers would most likely write you up if they heard about their officers making car stops off duty or taking action on minor stuff. If it was the case that it made you look better and the department wanted you do to that, I'd never get to go home....I'd be locking up the kids I drive past that are selling crack on the corner on my way home each day. And yes, as you said, its not 100% possible to leave your job at the door, but when you are off duty, there are a lot of things that you need to let slide....they don't pay you to be superman.