It's not one agent. It's two, which is just enough to turn his end of the car into a kill box.

Bucky lets off another burst and ducks across the car to the dubious shelter of the metal bins stacked against the wall. Bullets ricochet from the wall just behind him as he gets as low as he can and checks the clip to find that ammo's running low already.

What he's got will just have to do. Bucky plants his shoulder against the bins and rolls out, sighting and firing in the same movement.

One agent drops in his tracks; the other takes shelter behind the shelves in the middle of the car and keeps moving forward.