After you fight the Tiger tank, go back to where it spawned (south-west area). You should find a parked truck near the tower, and if you wait a little bit you'll also see a car patrolling to the north. It drives up and down the street on a loop.
Save your game in case something goes wrong!
Lay a land mine in the path of the moving car, then quickly run back to the truck and line up a shot on its weak point (or if you prefer, drop some dynamite beside it and take aim at that). When the mine goes off, shoot the truck within 5 seconds and the trophy should unlock immediately.