In my experience, and I used to get pulled over a lot, being courteous and respectful to an officer is sufficient to avoid a speeding citation with 50% success rate.
Anecdotally, my brother decided to splurge on his childhood dreamcar (a BMW Z3, second hand of course). He found that he started getting stopped for "random checks" once every couple of trips on the motorway. The probability would also be much higher if the car was freshly washed and shiny.
He then switched back to a normal, more "boring" car, and the "random checks" stopped.
Yep, I've noticed car choice mattering for myself and others as well.
Reflecting back to my original comment:
I guess my goal besides sharing my opinion was wanting to communicate to people who seemed to have the "just be polite and respectful view" is that factors like these make the predictability of politeness or respectability affecting the outcome at all way more variable.
FWIW, I'm white and very aware that it may be different if you are not. I thought about it when writing my comment but decided I m just didn't want to drag it into this discussion.
In my experience, it never hurts to be polite and respectful, though even as a white person I've had run-ins with officers who were either in a bad mood or just jerks and no amount of good will on my part seemed to matter. So it didn't help, but giving them lip would've just antagonized them further.
So yeah, maybe it doesn't help. But I can't imagine it would ever hurt.
And finally: I can only reflect my experience as a middle-class middle-aged married straight white Jewish male who's lived a relatively privileged life. I acknowledge that in its entirety. And I'm certainly interested in hearing other folks' experiences and learning from them. If someone wants to chime in about that time they were polite and respectful and it made the situation somehow worse, I'm all ears.
Poor, young, black and male are the high crime demographics that get drilled into officers' heads at the academy. People checking more than one of those boxes rarely catch a break.
However, I noticed that after growing long hair more citations would stick too.