As has been said by a few here before, alot of the attitude that people get from cops is a reflection of what has been dished out to them. I personally have never copped a yellow sticker or had the bad cop scenario. In my 15 years since I got my license I have probably been pulled over half a dozen times or less. Alot of it is probably luck but also if you give out the respect that you deserve then you shouldn't have too many dramas. I was let off for speeding at one point and I was honest with the cop that I knew exactly what speed I was doing, I just didn't realised it had dropped from an 80 to a 70 zone.

Not saying that it doesn't happen but alot of the time I reckon a sticker can be avoided by pulling your head in, keep your car clean and legal looking, and if you fuck up, be straight and admit it.