The only track that a Mercedes-Benz G-Class 4×4² should ever be on is the type that comes from following another vehicle off-road. In this video, we see the rugged SUV lapping the Nürburgring Nordschleife, though, and it's an odd sight.

The tyres on the G-Class 4×4² squeal loudly as the big SUV takes the 'Ring's corners. The body rolls considerably, too. Don't expect this rig to manage anything close to the record lap time when production is complete.

Gallery: Mercedes G-Class Squared new spy photos

In comparison to the standard G-Class, the 4×4² features a revised front fascia with enlarged openings in the corners and what appears to be a slightly bigger inlet in the centre. The front grille is blacked out on this development vehicle, but it's not clear whether this would be a production element or just part of the concealment for this one.

The large, camouflaged section above the windscreen is probably a light bar, and there's a big roof rack. A ladder on the hatchback provides easier access to the stuff a person is hauling up there.

The SUV also has much wider wings/fenders that cover tyres with bigger sidewalls. The engineers also lift the ride height for even more ground clearance. There are larger brake calipers, too.

At the back, there's a different spare wheel carrier with a mounting that appears to let it swing out of the way. A tweaked rear bumper has a metal bar under the G550's stock piece that might also function as an initial step up to the ladder.

Gallery: Mercedes-Benz G-Class 4x4² Spy Photos

The powertrain for the new G-Class 4×4² remains a mystery. It's safe to expect a variant of the 4.0-litre twin-turbo V8 to be under the bonnet. Expect the engineers to beef up the drivetrain with stronger differentials and axles to withstand more rugged driving conditions.

A debut date for the more rugged Mercedes SUV is a mystery. There's a possibility of it arriving before the end of the year. Regardless of when the unveiling happens, look for sales to begin in 2021.