Brabus has modified the Mercedes-AMG GLC 63 S. The implicit assumption then, is that AMG’s twin-turbo V8 SUV is underpowered. And slow. A strange mindset when approaching something already packing 503bhp and the ability to hit 100kph in 3.8secs.

Alas, Brabus has done what Brabus does. The 4.0-litre bi-turbo V8’s ECU has been treated to a new “plug-and-play” control module that adds new mapping for the injection and ignition, and ups the boost pressure.

The result is an additional 88bhp – to make a grand total of 591bhp – and a peak torque output of 800Nm, up from 700Nm. That latter figure is available from 1,750rpm.

The tweaked V8 is matched to a nine-speed automatic gearbox (from the E63), and a stainless steel exhaust system that reduces back pressure. The result in performance lops two tenths from the GLC’s 0-100kph time, now down to 3.6secs.

Elsewhere, there are carbon fibre body components to help optimise aero and intimidate puny earthling motor vehicles, lightweight forged Brabus wheels ranging from 19in to 22in in size, air suspension that drops the car by 30mm, and plenty of customisation for the interior. Think Alcantara, lots of leather, any colour you desire and carbon fibre.

As ever, you can order the complete car or take your own underpowered, slow GLC 63 S to Brabus who will remedy the problem*.

*We jest, of course. The GLC 63 S is stupendously fast enough and a riot to drive. Read our review here