Imaginary quota is jumbo shrimp. The only reason quota would ever be an issue is if they were under a certain quota at the end of the month, which would means solid numbers were involved where they needed to pull over X cars but they only did Y and now they need to catch up to the difference. Without numbers the principle of a quota is useless because there is no determined goal to meet.
I know cops and sheriffs that rarely give out tickets. Generally they pull anybody over for equipment violations (lights, inspection) and it just leads to bigger things as they pull those over (like in the situation with my friend), however their numbers are still extremely low and it doesn’t matter.