I dont know about armored cars, but when I was at EWR
one day watching departures a EL AL pick up truck parked right next to me.
He stayed there and talked on his radio untill the El Al jet departed, then he left.
It was not an armored car, and it was just one guy who didn't look to intimidating. He just sat there and watched the aircraft untill it left, all the while talking on a radio, he didn't seem to be concerned with me.
I wasn't out of my car, and neither was he.