Most people enter their mid-life crises around the age of 45, during which they would do pretty much anything to make themselves feel young again. For its 45th anniversary, Brabus celebrated the only way it knew how – no, not by buying a Porsche or getting a mistress. Instead, it has built a bonkers off-road machine with no doors, no windscreen and enough power and torque to spin a small planet.

Welcome, boys and girls, to the Brabus 900 Crawler, a crazy car from a company not exactly known for being a shrinking violet. Despite what the looks would lead you to believe, this hardcore 4×4 isn’t based on the Mercedes-Benz G-Class, but a bespoke tubular frame made from high-strength steel, and in spite of its name, the Crawler is built for high-speed desert running rather than climbing over rocks.

Part of that name is correct, however. The Mercedes-AMG M177 twin-turbo V8 has been bored out from 4.0 to 4.5 litres and pumps out a heady 900 PS at 6,200 rpm and a ridiculous 1,250 Nm of torque at 2,900 rpm. The gains come from forged pistons, precision-balanced connecting rods, a billet crankshaft and Brabus’ own turbochargers generating up to 1.4 bar of boost. Oh, and a Brabus active exhaust for good measure.

Unfortunately, the company had to limit the torque output to just 1,050 Nm, presumably to stop the AMG Speedshift MCT nine-speed automatic gearbox from turning into shards of toothy metal. Even hamstrung like this – and with a weight of more than two tonnes – this behemoth sprints from zero to 100 km/h in a scarcely believable 3.4 seconds, although the off-road tyres stop it from going faster than the 160 km/h limiter.

The reason for all this weight – despite the Crawler’s bare-bones nature – is down to the hardware underneath. You get a permanent all-wheel-drive system with the G-Class’ triple electronic locking differentials, plus four-way adjustable aluminium dampers and suspension components milled from solid aluminium. These include the wheel ends, control arms, front subframe and the housing for the rear live axle.

To maximise off-road capability, the Crawler sports portal axles – just like the previous generation G 500 4×42 and AMG G 63 6×6 – that push the wheels below the axle centre lines. Together with the 20-inch eight-lug alloy wheels and massive off-road tyres, they allow the car to offer an impressive ground clearance of 53 cm, double that of the standard G-Class.

Paring back some of that mass is the carbon fibre bodywork and the aforementioned lack of doors and glass, the red structure/roll cage making itself visible in their absence. The mini-G-Wagen front end not only gives the Crawler a slightly cutesy look but has also been opened up as much as possible to feed the huge radiators. The bonnet incorporates an air intake for the engine as well as vents that enable heat to escape.

Along the side, fat wheel arches (with gaping vents at the front) house the large wheels and tyres, and the wide rocker panels are strong enough to function as side steps. The roof consists of a simple carbon panel to keep the sun out and comes with fresh air vents and twin LED light bars.

Moving to the rear, the Crawler gets slim G-Class taillights, a sizeable roof-mounted wing and a full-size external spare, along with a quick release for the 100 litre racing fuel cell. The beefy skid plates front and back also mean you don’t have to worry about hitting that sand dune flat-out. Just…try not to roll it, okay?

Not that you wouldn’t be well-protected if that happens, with four carbon bucket seats and four-point harnesses keeping you strapped in. Brabus hasn’t skimped on luxury here, upholstering the seats in searing red quilted Silvertex – a high-tech, hard-wearing fabric derived from the company’s speedboats that are water-, dust- and fade-resistant. The “B” badge is embroidered into each headrest.

The front of the cabin will look familiar to Mercedes owners, with an AMG flat-bottomed steering wheel (replete with larger paddle shifters and the optional drive buttons with colour displays) and a widescreen display panel with twin 12.3-inch screens. The starter button, the electronic parking brake lever and the G-Class’ recognisable triple locking diff buttons are mounted on the central tunnel.

Hardcore desert racers will be pleased to know that the Crawler comes with a dedicated GPS navigation system ahead of the front passenger and an intercom system that allows occupants to hear each other over the sound of the wind, the sand passing underneath and that fearsome engine. Brabus has gone to town with the crimson hue here, which adorns the steering wheel, GPS display holder, footwells and even the pedals.

How much for all this extravagance? Well, the Crawler retails at €749,000 (RM3.4 million) without tax, which is a lot for a toy that, let’s not forget, is not road legal. Just 15 will be built in total – five this year, five next year and another five in 2024.