Welcome to one of the fastest four-door cars in the world – a Mercedes-AMG GT four-door that’s been Brabus’d to within an inch of its life.

It’s called the Brabus 800 because it has a nice, round 800hp. That’s 789bhp in old money – 158bhp more than standard, thanks to a pair of new turbochargers and different control software. Peak torque is up too, by 100Nm to 1000NM.

It is therefore rather rapid – 0-100kph in 2.9 seconds with an electronically limited top speed of 315kph. If the 800 wasn’t pegged-back, we’re in no doubt it could do well over 322kph.

A stainless steel exhaust offers quiet “Coming Home” and certainly not quiet “Sport” modes, and the air suspension has been reprogrammed to settle 25mm lower. Meanwhile, bare carbon bodywork is supposed to make the 800 more stable at speed (and more interesting to look at).

Other visual mods include the wheels, which are 21s at the front and 22s at the rear, the black/white leather interior and the many, MANY Brabus badges scattered about the place.

What does it all cost? Brabus won’t say, but expect a significant increase over a normal, £130K GT63S.