There is a certain brutality to the current range of AMG Mercedes products that we find ourselves giggling about like school children, every time we get behind the wheel.It\u2019s no different in this, the newly updated E63 AMG. Along with the rest of the E-Class range it has just undergone a heavy facelift. This has shorn the car of its four-lamp front end and the rather contrived "Ponton" line that once adorned the rear wing and door surface. In their place you get cleaner lines, but a slightly more \u2018melted\u2019 looking set of front lamps that don\u2019t quite say \u2018Mercedes\u2019 in our view. As we shall see though, this is quickly forgotten about once you\u2019re behind the wheel.The E63 badge is something of a misnomer though. Once upon a time, the number in a Mercedes badge stood for the car's engine capacity. So you might think that "63" means this is a 6.3 litre fire-breathing monster engine. In fact, it's "only" a 5.5 litre, but the "Bi-turbo V8" script on the front wing tells you all you need to know. It might not have quite the cubic capacity you'd think, but the fire breathing capabilities are all present and correct.Thunderous" is a good adjective to describe its delivery. It starts up with a boom from the exhaust and even when you\u2019re trickling out of the car park the intent is there \u2013 you can feel it straining at the leash.Yet inside, you can be having a lovely serene time in the proverbial drawing room on wheels interior. We\u2019re not really ones for wood in cars, but the optional \u2018Brown, open-pour ash wood\u2019 (\u00a3285) of our test car was really rather lovely.We can\u2019t make up our minds as to whether it clashed or complemented the other bits of \u2018AMG-ness\u2019 that are thrown at the otherwise normal E-Class cabin though. There is a suede-trimmed steering wheel, IWC clock and elements like the drive mode selector and three AMG\/damper\/traction buttons that are twisted out of axis, presenting themselves temptingly towards the less scrupulous driver \u2013 as if to say "go on, press us, be naughty and make things more fun". These, along with the stubby, Affalterbach crest-embossed gearshifter could have been lifted straight out of an SLS. Come to think of it, they probably have.And it would come as no surprise to learn that the E63 wasn't far behind the SLS in terms of outright performance although we weren't able to contrive a drag race with one, sadly. On occasion, you can just about tell the engine is turbocharged, but that\u2019s no great problem \u2013 in all conditions it remains describable in one simple word: fast. And the noise it makes is blaring V8 great, letting out a delicious "woofle" as you flick the (lovely to use) paddles to come down the gears.Special word to the (\u00a31090 optional) dynamic multi-contour seats too \u2013 these can pummel and massage you, but more importantly have side bolsters that inflate and deflate to counteract the cornering forces you\u2019re exerting. Steer hard round a right hand bend and the left-hand bolster firms up, holding you in place. Which is actually rather disconcerting and mildly hilarious \u2013 we suggest you bring a passenger along, don\u2019t tell them and then see how long it takes them to freak out.Of course, 73 grand might seem a lot for something that's based on Germany's default minicab vehicle and which can be had in basic form for around 30k. But to make that assumption would be to do a great disservice to AMG's engineers. Because they've transformed a large executive saloon into something that will spit you down the road at eye-watering speed and readily indulges people who like to spend their lives looking out of the side windows \u2013 rather than the front windscreen \u2013 as they go round corners.No, the real question with this car is more what kind of person you are. It\u2019s actually rather discrete \u2013 especially in Palladium Silver. Which some will like a lot. But the same powertrain is also available in the much more eye-catching CLS and for those who like a bit of bling and to show off in their lives, we can see an argument for how a white CLS 63 might fit a little more amusingly with the car's dynamic demeanour.Alternatively, you can revel in the absurdity of it all, and have your E63 AMG in estate form \u2013 which is perhaps the quickest and most expensive means yet created of guaranteeing your dog(s) will be sick, should you ever choose to fill the vast cargo space with Fido.Whichever flavour of AMG "63" you choose, we reckon you\u2019ll not stop giggling every time you bury the "loud" pedal. And unlike most sports cars, there\u2019s plenty of room for your family and friends to come along to share, or be scared by, the visceral experience that only an engine as mighty as this is able to give.