There was a point, I admit, when driving this latest AMG hot rod, that I failed to see the point of it. Does a car like the CLS actually need to deliver a punch as mighty as this? Of course it doesn\'t. The fault lies with me - I need to regroup, recalibrate my senses, get to grips with this behemoth. Because it\'s an absolute brute and normally I fall head over heels in love with cars that drive like this. The normal CLS is a fine car, of that there is no doubt. And the ones I\'ve driven so far haven\'t exactly been slouches - on the contrary, they\'ve been powerful, rapid and refined; a recipe that, if tinkered with, could be a disaster. Yes, I know the looks are a bit odd but the front end, at least, is a success. And the CLS can rightly claim to have reignited our interest in four-door coupés (Mercedes can\'t lay claim to have invented the segment; even Rover had one - the iconic P5B coupé - in the 1960s) because, in 2004, when the first model broke cover, nobody else was building anything like it. The current model isn\'t quite as satisfying to look at but then that\'s only ever part of the story. This is the AMG one. The hot one. The criminally insane one. The unnecessary one. But, as I remind myself, just because something is unnecessary, that doesn\'t always make it nonsensical. On the contrary, I enjoy a bit of frivolity now and then. It\'s just that cars this stupendously quick normally have two doors, two seats and are wildly impractical. I\'m still confused. What is this car for? It\'s obvious once I\'ve spent another day inside its glorious cabin: its pointlessness is its very point. I need to lighten up, evidently. And I do, every time I squeeze the throttle and 900 (900!) Nm of twist throws me down the road like some gigantic leather-lined catapult. The car I\'m driving has been fitted with AMG\'s \"Performance Pack\", which boosts power from 525 to 571hp and torque from 700 to 900Nm. Driving this thing on a normal road is definitely like using a sledgehammer to crack a nut, and mainly this is down to the hand-built engine, which is nothing short of a masterpiece. A bit like BMW these days, seeing a number on the flanks of a Merc doesn\'t give an accurate indication as to what\'s under the bonnet. The CLS 63 used to have, you guessed it, a 6.3L naturally aspirated V8. Now there\'s a 5.5L V8 under the bonnet. But here\'s the good news: it may have lost 0.8L of cylinder capacity but it gained two turbochargers. Nice. And even the green brigade can take solace in the fact that, as is always the way, the new motor is 25 per cent more economical. And if you\'re wondering about longevity, it\'s worth noting that the engineers responsible for developing this car put in more than a million kilometres behind the wheel to make sure it\'s as good as it can possibly be. Normally, big Germanic cars like this are cursed with steering that\'s as lifeless as a corpse. Not so here. The electro-mechanical set-up is 22 per cent quicker than in the normal CLS and the feedback is extraordinary, while the entire chassis seems to communicate a huge amount of information about the road surface to the driver via the wheel and the seat. Yet, and this is the most amazing thing, it still retains enormous levels of refinement and long distances can be covered without even the merest hint of fatigue setting in. The car fizzes with a maniacal energy. It rumbles deeply, hinting to pedestrians and anyone sat next to you at the lights that it\'s not to be messed with. From / The National