New 888-HP Brabus Rocket 900 Poses With CLS-Based 788-HP Rocket 800 Predecessor 14 May 2021, 15:22 UTC · by When Mercedes decided against building a flagship AMG spec for the third-generation CLS, we should have known there and then that once Brabus started looking for a new Rocket candidate, they would automatically exclude the latest CLS and opt instead for another nameplate. 8 photos Naturally, the folks from Bottrop went with the Mercedes-AMG GT 63 S four-door model, which on paper looks like the ideal starting point for creating one of the world’s fastest sedans (or four-door coupes). In other words, the blueprint was already there thanks to that twin-turbocharged 4.0-liter V8 engine and its stock 630 hp (639 PS) and 664 lb-ft (900 Nm) of torque.