This is the monstrous 740bhp twin-turbo Brabus S V12 R, which the German tuner is set to reveal at this month's Frankfurt motor show.
You've got to hand it to Brabus. Faced with the 510bhp S600 Limousine, most tuners would pop a set of big alloys on, a body kit of dubious taste and leave it at that.
Instead, Brabus gives us mighty horsepower with a host of engine modifications, including forged pistons, tweaked cylinder heads, revised camshafts, a new crankshaft, larger turbochargers, a more efficient intercooler, a high-performance stainless-steel exhaust, and an uprated ECU. There's also the small matter of a 0.8-litre increase in swept capacity as the SV12 R's engine has been bored out from 5.5 to 6.3 litres.
Torque is up from an already healthy 612lb ft to an electronically limited 811lb ft (the transmission won't take any more twist!) and this, combined with the monumental power output, means that the Brabus SV12 R can claim some genuinely mega performance figures. 0-60mph is achieved in 4.0sec, while 124mph (200kph) arrives after just 11.9 seconds. Top speed is an electronically regulated 211mph.
To help haul the SV12 R down from these massive speeds, the car gets 12-pot calipers grabbing on to 380mm ventilated and cross-drilled discs at the front, and six-pot items with 355mm discs at the rear.
There's only one flaw, as far as we can see - that interior trim. We don't mind the body kit, and we don't even mind the various choices of big alloy wheels, but that weird, pin-stripe leather is, frankly, a bit odd. Brabus says that "as a stylish and perfectly crafted complement the company upholstery shop created an elegant fully leather interior in a combination of light-beige and dark-brown leather that is especially soft, breathable and extremely durable." We rather wish they hadn't.