A BMW M4 review. Is this another special edition?Yes. It's the BMW M4 CS. If you know your M cars right down to their model codes, you'll immediately recognise how cool those two letters are. If you don't, think of it as the middle ground between the regular BMW M4 and the bonkers, two-seat BMW M4 GTS.It sits between the two very well, in fact. Its 454bhp power output and 7m38s NÃ¼rburgring lap all place it roughly halfway between the M4 range's book ends.So what's new?Every component has been sharpened up from the standard M4. The stability control, brakes, suspension, steering, differential and paddleshift gearbox all have a unique tune for the CS.The 3-litre twin-turbo straight-six engine is 10bhp healthier than an M4 Competition Pack, and 29bhp better off than a regular M4. The result is a 3.9sec 0-100kph time and a 280kph top speed, the latter electronically limited.The wheels are a new 10-spoke design inspired by the M4 DTM racecar, and measure 19 inches at the front, 20 inches at the rear. The staggered setup is borrowed from the more senior M4 GTS, and aids grip at the rear.Those wheels come as standard with Michelin Pilot Sport Cup 2 tyres, which inhabit the more extreme end of road-legal rubber. If you'll be using your car in wet conditions, BMW will also offer you regular Michelins with more everyday-useable tread. We fear the dealer may make clucking noises and mime chicken wings if you ask for them, though...Has weight been saved?At 1,580kg, it's around 30kg lighter than a paddleshift-equipped M4. More GTS inspiration has arrived in the form of a carbonfibre-reinforced plastic bonnet. As well as looking fantastic, it helps lower the centre of gravity, which in turn helps handling. The rear diffuser is borrowed from the M4 GTS, while the carbon 'Gurney flap' spoiler is new for the CS.The interior is more focused, too. The regular door inlays are replaced with 'compacted natural fibres', material that's renewable as well as supremely light. There are no arm rests anywhere, fewer stereo speakers and a simpler air con system. Regular door handles are swapped for canvas straps and there's a magnificent pair of sports bucket seats, manually rather than electrically adjustsabile. Both are interwoven with the M tricolours, obviously.Mind, it's not a total makeover\: there are still back seats, there's plenty of leather, and the front seats even get illuminated 'M' logos on them. Most of the regular M4's option list remains at your disposal, too.So how does it drive?Very, very well. This is one of the cars that feels expertly set up right from the off. Hold the Alcantara steering wheel, let off the manual handbrake and pull out of the car park and there's such accuracy and satisfaction from each control, you'd conclude it's brilliant without actually going much quicker.Naturally, though, it gets better the more revs you use, and the further you dig into its deep reserves of grip. The larger rear wheels (and therefore tyres) help make this an M4 you can fully trust, one that's predictable and not liable to give you a mid-corner fright. In the dry, at least. We've not had the chance to try it in the wet...Much like the Mercedes-AMG GT R we've recently driven, it's an example of a track-minded special being a much better and more approachable road car than its base model, rather than being spiky and intimidating.The CS is tangibly more athletic than standard - there's naff-all body roll - yet it sends more information through its seat and steering wheel. Its extra focus leads to a more communicative car, which breeds more confidence from its driver, who in turn works the car harder and has more fun. It's a virtuous circle.Bet it's really firm, though...As you'd expect, it's not a plush, cossetting vehicle. But the body control is seriously impressive and there are worthwhile differences between each of the adaptive suspension's modes.Adjustable through Comfort, Sport and Sport Plus (the steering and engine/gearbox are, too), you can actually use the toughest setting on the road without making the car a minor handful. You'll probably want Sport for an undulating B-road, mind. In Comfort it ought to be an amiable everyday car.How's the engine?More characterful. There's a sports exhaust - previously optional on the M4 via the Competition Pack - and if you've prodded the drivetrain into Sport Plus it rumbles loudly during acceleration and pops and crackles like nobody's business on a trailing throttle. Childish? Yep. But there's nothing wrong with that, not least because you can just prod back into Sport or Comfort when you're bored of it.With just 10bhp more than an M4 Competition Pack - despite costilng a fair bit more - this CS doesn't feel night-and-day quicker. It does have a lot more torque, though, its 599Nm matching the M4 GTS. This actually helps make it feel supremely useable, and alongside the standard (and brilliant) seven-speed paddleshift transmission, makes this an easy car to nose around town in.Very sensible thing to point out...Yeah, but it's quite key, that last point. This isn't a highly strung track special that needs utmost commitment to work properly. It's a car that is only ever a button press or two away from matching whatever mood you're in. It feels more approachable to drive than a regular M4 while possessing more drama when you're pushing on. Something which you'll be more inclined to do, because of how much happier and more confident you'll be behind that Alcantara wheel.The best M4 yet? Probably. It's the sweet spot in the range, and whatever you think of the price, BMW won't have any problem selling every single one made between now and 2019. It's a useable four-seater with a light dusting of track-nutter magic. It's brilliant.