Yes, be cooperative, but not cooperative to the point that you give them more rope to hang you with.
I used to be a volunteer fireman, and on occasion I rode along with one of the town cops. One day that stands out in my mind in particular, 20 years later, was when we were going east on a 2 lane road, posted limit 35. A car going the opposite direction was going 47. Jerry turned on the lights and stopped, right there. The car drove right past us. Jerry put it in reverse and backed up, keeping up with her for a short distance, before he turned around and pursued, finally getting her attention with a quick tap of the siren. "She's DEFINITELY getting a ticket," were the words he said upon exiting the car.
A few minutes later, he came back and wrote her a warning. I don't remember now what the reason was that she gave him for being inattentive, but whatever she said turned a cop around who was quite angry with her for her inattentiveness.
Recently, I got a ticket for improper lane use. I passed a car in the right turn lane, when the car in front of me stopped to turn left. Perfectly legal in most of the places I've lived, but what I hadn't noticed before was the sign that said right lane must turn right. Ok, fine.... The only problem I have with it is that one of the young ladies at my church passed me while I was pulled over, so that night at church, she told me of how she got a warning for the same thing, in the same place. Turns out, I guess, that you have to have different anatomy to get off like that....