- many cops saw PBA cards as corrupt and insulting. So the rule of thumb was you never offered these, you just let the card be visible when reaching for your license. If the cop was in on it they'd then ask you about where you got the card. It was a huge no-no to offer it not just because some cops didn't take it but because even those who would could probably be offended by you not deferring to their authority to decide to ask about it (ie offer to give you a pass) or for being entitled. The net dynamic you wanted was the cop to of his own volition see the card and decide if he wanted to cut you a break since he knew you were connected to the police somehow. (Ie, total corrupt dynamic)
- a big variable was if they took the card or let you keep it. If you were a son or daughter of a cop you probably never got it taken. Otherwise you'd get it taken if you would have otherwise gotten a ticket. If you were just being pulled over for no good reason they'd probably not take the card from you so you could "use" it again.
- these were not gonna get you out of trouble if you did something more than speeding, talking on a cell, etc. If you ran a light or stop sign it was borderline. If you committed a felony or were drunk etc then flashing your PBA card probably would have made your life worse.