The Mercedes-AMG SL is well known for being a convertible, so being turned into a fixed-roof shooting brake was not among the list of modifications I expected Brabus to make to the car.

However, the brand known for its high-powered Mercedes-based creations has been expanding its portfolio in recent years, turning its hand to models from Porsche, Range Rover and even Rolls-Royce. Customised interiors, enhanced bodywork and increased performance have been the bread and butter of the company, but the Rocket GTS shows off the coachbuilding part of the Brabus playbook.

Starting with an SL, almost every visible element is new, with only the doors, wing mirrors, windscreen wipers and lights being carryovers from the base model. The shooting brake profile is the star of the styling show, with the solid roof extending towards the rear axle. This is met by a rising windowline that accentuates the new rear haunches, giving the car a 1.95-metre width. A bespoke bodykit also widens the front of the Rocket GTS, with a redesigned lower bumper that improves cooling and decreases lift on the front axle.

A tailgate-mounted spoiler sits above the integrated ducktail at the base of the hatch, and a new rear diffuser – flanked by four illuminated exhaust pipes – completes the aerodynamic package and the near-exclusive use of carbon fibre for the exterior. Brabus promises that the Rocket GTS delivers outstanding driving stability even above 186mph. The car looks ridiculous in the best possible way to my eye, reviving the super shooting brake body style last seen on the Ferrari GTC4Lusso, itself an evolution of my favourite model from Maranello – the FF.

The Rocket GTS is based on the SL 63 plug-in hybrid, which has one of the most potent powertrains I have ever encountered, but with this being Brabus, 805bhp from the 4.0-litre V8 and electric motor won’t quite cut the mustard. The engine’s displacement is increased to 4.4-litres and is fitted with bespoke pistons, connecting rods, turbochargers, 75mm downpipes, and a new crankshaft. An additional ECU and a new 76mm exhaust bring the engine power output up to 785bhp and an electronically limited 774lb-ft (1,050Nm) of torque.

The electric motor is mounted on the rear axle and features its own two-speed transmission so that electrical assistance can be called upon at a standstill or at the 197mph top speed. Drawing power from a small 6.1kWh capacity battery, this adds a further 201bhp and 236lb-ft (320Nm) for a combined maximum output of 986bhp and a mighty 1,195lb-ft (1,620Nm), which, mercifully, is transmitted to all four wheels via a 9-speed automatic transmission. From a standing start, reaching 62mph will take just 2.6 seconds, and 124mph will flash by after 9.5 seconds. Most impressively, the car will reach 186mph in 23.6 seconds.

Bringing the Rocket GTS back to earth are the carbon ceramic brakes that sit behind the newly designed “Monoblock P” forged rims, which feature carbon fibre inserts to improve aerodynamic performance. These staggered wheels are wrapped in Continental Sport Contact 7 tyres that measure 275/35 R21 at the front and 335/25 R22 at the rear.

The interior has been completely retrimmed by Brabus, with a mixture of leather, carbon fibre and Alcantara to be found on every surface. A seashell pattern adorns the leather of all four seats, the central and door-mounted armrests, and even the floor mats. The pedals, door sills and dashboard trim are made of carbon fibre, and the steering wheel carries both of those materials. The Rocket GTS wordmark appears in badge form by the glovebox and is pressed into the bolsters of the front seats, which feature heating, ventilation and the Airscarf neck-level heating system from the Mercedes-Benz convertible range.

The Rocket GTS retains the 2+2 seating layout of the SL on which it is based, and both rear seats have ISOFIX mounting points for child seats. The elongated roof means that rear occupants can enjoy much more headroom than is found in the new Mercedes-AMG GT – a car that requires the boot to be open for me to sit up straight in the rear. The estate bodystyle also means a larger boot is accessible, although it is a two-tiered storage area owing to the high-voltage battery sitting above the rear axle and taking up space.

Rocket models from Brabus are always built in extremely limited numbers, and although there has been no indication of the size of the production run, one example is currently being listed for €945,000 – roughly £792,000 – and I’d expect a bespoke commission to cost slightly more.

Following its reveal at the Brabus Signature Night, the Rocket GTS has been splitting opinions across the internet and here at RUSH Magazine, where I am in the minority of fans of the roadster-turned-shooting brake. Founding Editor Craig Toone said, “I know it’s Halloween, but I did not expect to have nightmares about a BRABUS Frankenstein. This is an insult to the BMW Z3 M Coupé – all that’s missing are some 4D plates and Mansory badges.” Staff Writer Aaron Stokes refused to comment. 

It is impossible not to view the hybrid hyper-estate as ridiculous because by its very definition, it is. Who thought that a convertible-based, coachbuilt shooting brake with as much power as a Bugatti Veyron was worth doing? Clearly Brabus did, and I’m glad. After all, anything worth doing is worth overdoing.