Can’t tell what the vehicle is that’s taking aim at phoney Joni. It is not American, though. All US light armor uses small (<25 mm) automatic guns. It might be a British Scorpion with the 90mm Cockerill gun, since some of these have been sold to collectors here.
It’s a sure thing though that the Meal-Teamer standing directly in front of it did not drive it there, since he obviously would not fit through the hatch.