GENEVA MOTOR SHOW: Mercedes-Maybach Landaulet revealed

The G-Wagen came in to the world as a tough all-round, off-roader and it goes out as a pinnacle of ostentation in the Mercedes-Maybach G650 Landaulet.

Based around the architecture of the G63 6X6 AMG, the long-wheelbase Maybach turns the 1979 G-Wagen into a hard-core, high-rise limousine with an open-topped cargo area.

The four-seat Maybach takes the 39-year-old G-Wagen and makes it longer, wider, more powerful, more luxurious and gives it even more off-road ability with the adoption of the Unimog’s portal axles and 325/55 profile 22-inch tyres giving it 450mm of ground clearance.

At 5345mm long, it gets more than half a metre of wheelbase stretch compared to the G500 4x4 Squared and, at 2110mm wide and 2335mm high, it’s going to demand an enormous garage to house it. It’s so big that its 3428mm wheelbase is 258mm longer than the standard S-Class limousine.

It will take an enormous wallet to buy it. Just 99 versions are being built by contract builder Magna Steyr in Graz, Austria, and Daimler officials suggest it will be even more expensive than 2014’s outrageous €480,000 G 63 6X6.

It will take an enormous wallet to run it, too, with the 465kW twin-turbo V12 slurping down fuel at 17.1 litres/100km - and that’s on the combined urban/extra urban cycle of the NEDC. The coinciding CO2 figure almost breaches the 400-gram/km barrier.

So, while its well-heeled customers will barely care (indeed many of them will be pumping the oil out of the ground in the first place), generating 1000Nm of torque from 2300rpm will mean Daimler will need to sell plenty of Smart Fortwos to offset the emissions of each Landaulet.

The V12’s drive runs through a seven-speed automatic transmission before moving through an all-wheel drive system with three differential locks (which can be locked or unlocked while driving) and a low-range transfer case.

Though Mercedes-Maybach is taking a leaf out of the Rolls-Royce book by not claiming a 0-100km/h time or a top speed, the lighter G65 AMG uses essentially the same powertrain and hits 100km/h in 5.3 seconds and is limited to 230km/h.

Once near moribund as a brand, Maybach has come back as a flagship atop Benz’s traditional models. The G650 Landaulet boosts the number of Maybachs at Daimler to five, but there’s really nothing traditional about it.

The roof introduces a semi-convertible setup, which takes its inspiration from the 2007 Maybach 62 Landaulet, and will be publicly seen for the first time at the Geneva motor show early next month.

It’s so tall that the G650 Landaulet uses a standard running board to allow people to climb into it, and that’s not something you see every day. But the interior looks like it could be worth the climb.

All four seats are borrowed from the S-Class Pullman and are electronically adjustable and, obviously, lined in leather. Naturally, they deliver a hot-rock massage function and massaging air chambers.

There were hints (provocatively teased by Mercedes itself) that the G650 Landaulet would be a full convertible and that the four occupants would be housed beneath a steel roof. However, on the production car an electronically controlled fabric section will retract into the luggage area behind the back seats.

The rear passengers haven’t been forgotten, with two 10-inch display screens mounted on the sound-proof glass partition between the front and back, held up with a new cross-member.