I just checked Road Rage, and there is only one BMP-2 on that whole map, and he's in the second area (and not invulnerable or anything).
That guy traveled quite some way to attack the ground forces, and survived all of those shots by simple good fortune. I was trying to get the Warthogs in on him but he vanished behind a hill the second my laser touched him.
"It is necessary to develop a strategy that utilizes all the physical conditions and elements that are directly at hand. The best strategy relies upon an unlimited set of responses."
-- Ueshiba Morihei