Got a Mercedes-AMG GT 63 S four-door but you wish it had more power and presence? Then German tuning house Brabus can provide. This is the Brabus 800, displayed at the Top Marques Monaco show, and it uses the 639hp/900Nm GT 63 S with the 4.0-litre biturbo V8 as its basis. Brabus then fits two bigger turbochargers, fiddles with the ECU, adds its own stainless-steel exhaust and exterior carbon-fibre aerodynamics package, bolts some 21-inch front, 22-inch rear Monoblock Z 'Platinum Edition' alloys onto the axles and then gives you the whole lot back, now sporting 800hp at 6,600rpm and 1,000Nm at 3,600rpm. The result is a 2.9-second 0-62mph sprint, which is three-tenths quicker than the 639hp GT 63 S, although the top speed of 196mph is identical - Brabus has to limit the 800 to this, presumably for the sake of the poor tyres (which are 335-section on the rear with a farcical 25-profile). Inside, buyers can select from a 'virtually endless' combination of colours and finishes for the leather and Alcantara upholstery choices, and the Brabus 800 can either be bought as the whole car or you can add the upgrades to an existing GT 63 S AMG.