The 800 E V12 does 0-100kph in 3.7 seconds, breaking the 300kph mark in less than 24 seconds. Image Credit: Supplied picture

After going wild with the Mercedes E-Class saloon and coupé, the guys at German tuning firm Brabus have laid their hands on the E-Class cabrio. Madness ensues. And that madness has ensued all the way to Dubai for the world unveiling of the Brabus 800 E V12 Cabriolet, the most powerful and fastest four-seater drop-top on the planet.

Not content with merely squeezing in a V12 lump from the S600 into an E-Class cabrio's engine bay, Brabus heavily tuned the lump to deliver 800bhp and an almost unmanageable 1,420Nm of torque. Displacement has been bumped up from the stock 5.5-litres to 6.3-litres thanks to a special crankshaft with a longer stroke and larger pistons to fill the bored out cylinders.

Mated to a seriously beefed-up five-speed automatic transmission — and it needs to be beefier than an Aussie T-bone to cope with all that torque — the engine kicks up its power at 5,500rpm. In fact, even with an uprated gearbox the Brabus guys simply had to take it down a notch to 1,100Nm with an electronic limiter. But still, it's certainly not lacking in that department. With these ludicrous figures, the 800 E V12 blitzes the 0-100kph sprint in 3.7 seconds, pummelling on towards the horizon and the 300kph mark in just less than 24 seconds. You'd think Brabus would be content with that, but you'd be wrong. The 800 E V12 Cabriolet's top speed is 370kph… yes, 370kph, making it the world's fastest four-door cabriolet.

To keep all this insanity somewhat planted on the road, the car gets a high-performance limited slip differential with a locking rate of 40 per cent as well as a full aerodynamic body kit incorporating a redesigned front apron to reduce lift on the front axle. It also channels more air to the greedy radiators and massive front brakes hiding behind the Brabus 19in wheels.

New fenders allow for a much wider track accommodating 9.5in of rubber at the front and 10in anchoring down the rear.

Brabus developed the suspension together with Bilstein to include 10 selectable settings, and the ride height can also be adjusted by up to 35mm to negotiate Jumeirah Beach Road's sleeping policemen. The passengers enjoy a combination of lipstick-red and black leather, with a Brabus steering wheel for the discerning owner and carbon-fibre trim. And it comes with a two-year, bumper-to-bumper warranty.

Would you like another ridiculous figure to finish it off? It's yours for just Dh2.5 million…