High-performance cars are all well and good but the appeal can wear thin after the umpteenth blast on an empty mountain road. After all, when you’re not driving quickly what can you do with them? Wouldn’t it be nice to have something that’s super-quick but also super-practical? And if you’re short of space outside your house, making it your only car would tick a lot of boxes. Regular cars that have been given a sizeable horsepower uplift are often described as ‘Q-cars’ because of their unassuming looks. The description is also valid if you want to combine everyday practicality with something that will give a Porsche 911 owner a hard time. Mercedes, through its AMG tuning arm, makes a good living selling such machines. A classic example is the firm’s C-Class estate, which is a fine load-lugger and refined car to drive in its own right. Stuff a 6.2-litre V8 petrol motor under its bonnet and it becomes a very different beast — a beast with 457 horsepower. In keeping with the Q-car theme, save for a few AMG specific details, the C 63 AMG could be a C320 CDI diesel with an AMG body kit thrown on. That’s the point, though; if you want to avoid the watchful gaze of everyone else on the road, this is the performance car to have. Yes it looks more muscular than a regular company car, but it doesn’t shout “Look how fast I can go!” despite the body kit. Only it does. The silence is broken when you start the C 63. And it’s also now that the car’s quad tailpipes — you won’t see these on a tricked-up diesel C-Class — come into their own. A short, sharp and oh-so-deep roar emanates from the tips on start up, and does much to set the tone for the rest of the driving experience. What will please the enthusiasts is that the C 63 is more than just a C-Class with a big engine and a fancy bodykit. Mercedes is at great pains to stress that a lot of work has gone into making the car quick, refined, manageable and fun. Suspension, steering, brakes and transmission have all been given the AMG treatment. The result is something special: a properly sorted performance machine to rival a conventional sportscar. And best of all, you can have an estate version with a 1,500-litre carrying capacity. Beat that Mr 911 owner. OK, so the C 63 isn’t a direct 911 rival, but if you just want one car that (almost) does it all, you won’t be disappointed if you opt for the C-Class. It has four doors and a good size loadspace, plus all the usual high-spec C-Class toys. And it gets even better. If you’re not content with ‘only’ 457 horsepower, you can pay Mercedes a bit more money and they’ll increase the output to 487 horsepower. These ‘Performance Package Plus’ (PPP) cars sport red brake callipers and, not so easy to see, a trick crankshaft, pistons and conrods. The end result is a really, really quick car. The on-paper figures don’t tell the whole story as the PPP-equipped car shaves just 0.2 seconds off the zero to 100kph time — 4.4 down from 4.6 for the regular C 63. The subjective feeling one gets when behind the wheel is of a much greater sense of urgency. Factor in the optional locking differential and you’ve got yourself a precision tool capable of slicing through bends with the polish of something with only two seats and no room even for a toothbrush. And all the time the car’s engine and exhaust note is front and centre in the cabin and insanely infectious. It’s also where the Q-car similarities fall down, because even when just ambling around town, the C 63 sounds like an old TVR — you know, the ‘proper’ ones powered by Rover V8 engines. You can hear this thing before you see it. Flat out on a suitable road and the aural assault intensifies. One can only guess what it sounds like from the outside, but that’s the least of your worries as you marvel at this estate car’s ability to cover ground at a ridiculous rate. That it rides in a way that’s best described as firm but fair and delivers plenty of feedback through its chunky steering wheel is proof that Mercedes and AMG really know their stuff. It grips, goes and stops like a proper sportscar. Its brakes and seven-speed auto gearbox respond well to quick, decisive inputs from the driver. Heck, even the stability control system can be fully switched off if you want to exploit the car’s true potential. Overall, it is everything a mature performance car should be: competent, fast, full of character, confidence inspiring, practical and, above all, fun. The C 63 AMG estate is a fine example of what can be achieved when convention is thrown out of the window.