G-Wagen, G-Wagon, G-Class: whatever you call it, there’s a reason Mercedes-Benz’s insanely competent off-roader is so iconic. The SUV has served in militaries, been a Popemobile, climbed 100% grades, and become a 6-wheeled desert-conquering pickup. And it’s that last part that’s curious. Off-road pickups like the F-150 Raptor and AEV Prospector are insanely popular, but …