What's all this about?

In the current wide pantheon of 'G8x' BMW M3 and M4 models, there is plenty of variety, and none more so with the hardcore, focused, special-edition models. So when we got an outrageous version of the G82 M4, with an extra 40hp and limited to just 1,000 units worldwide, it obviously took the hallowed name CSL. Then BMW did a version of the G80 M3 that was inspired by the look and intensity of the M4 CSL, but which had xDrive AWD and a less restrictive build run... and that created the M3 CS. So now we've got a coupe version of that latter car.

Right, so this is an M4 CS, then?

It is indeed. And the formula is much the same as the M3 CS, only in two-door format: as in, if you found the £128,820 M4 CSL just that bit too hardcore, given it had no rear seats and a whopping great price tag, or you simply missed out on one of the 100 examples that came to the UK, this M4 CS ought to serve as a fine 'second' prize.

It deploys the same M xDrive all-wheel-drive set-up as the M3 CS, as well as that car's eight-speed M Steptronic automatic transmission. Power comes from the CSL-spec straight-six twin-turbo, which means 550hp and 650Nm of torque (the former 40hp up on an M4 Competition's 510hp but the latter no different) - and that's good enough for a 3.4-second 0-62mph time, which is three-tenths faster than the M4 CSL could manage by dint of this newcomer's greater xDrive off-the-line traction.

The M4 CS has stiffer engine mounts than in an M4 Competition, too, so that the driver's sense of connection to the car is enhanced by rapier-like responses, while an uprated exhaust system with a titanium rear silencer should bring plenty of the good noise. Aside from that, it has extensive use of carbon-fibre-reinforced plastic (CFRP) to keep the overall bulk down, a useful 20kg being trimmed from the M4's porky 1,800kg kerb weight thanks to all of the CS's bonnet, front splitter, front air intakes, door mirror caps, rear diffuser and 'Gurney' rear spoiler being made of the stuff.

That diet includes the interior, where lightweight carbon buckets and a pared-back centre console are the hallmarks of the M4 CS. It does retain its rear seats, unlike the CSL, so it has a measure of added practicality as a result, but it also feels a little more special than an M4 Competition in here, thanks to the use of lots of carbon details and a bespoke red-and-black colour scheme. It's also, underneath it all, a facelifted 4 Series, so it has a new shape of air vents and BMW's latest iDrive Operating System 8.5 for the infotainment, while the flat-bottomed steering wheel is a fresh touch for BMW and is finished in Alcantara with a red 12 o'clock marker.

OK, talk to me about those exterior looks.

Some of the CFRP is left 'naked', so that you can see the weave and know you're looking at a CS trundling by, rather than a 'mere' Competition. In the headlights are yellow details, designed to make you think of the motorsport-spec M4 which competes in top-level GT racing, while at the back are the same distinctive Laserlight clusters from the CSL. Colours include the eye-catching Frozen Isle of Man Green metallic in the pictures here, although there's also a Riviera Blue solid option for those who want a little more aesthetic discretion. Wheels are 19-inch front, 20-inch rear forged alloys, available in finishes such as matte black or the distinctive Gold Bronze of the pictures, and tyre choices amount to some serious rubber - either Michelin Pilot Sport Cup 2 tyres, or optional Sport Cup 2 R items.

And how many of these are there going to be? What sort of pounds will I need to rustle up to have one?

Order books are open now and BMW UK says the first M4 CS models will be with customers in autumn this year. We're not sure on exact build numbers; maybe it'll be like the old F82 M4 CS, where BMW said it would build as many as production lines would allow, without saying it would be unlimited either. Anyway, if you fancy the CS's particular blend of attributes, it'll cost you from £117,100 - when a standard M4 Competition xDrive currently retails from £90,845. That's some chunky uplifting going on, although going on previous BMW CS experiences, this special M4 (likely to be this generation's swansong model) will almost certainly be worth the extra.