As a retired LEO and Instructor I agree 100% with all gmert has posted.
Others have posted various things.
I will remind you that your attitude will show and that will be responded to either positively or in a negative way. The traffic stop will be handled per the Officer in charge.
Make it easy on yourself and do not arouse undue suspicion by your words or actions. The general public would be surprised as how their actions play a part in the overall picture. The world is getting more hostile and all Officers now are more cautious than ever.