What’s new?It may look like a Z4M Roadster with a roof in the photographs, it may seem even more like one when you look at its near-identical spec sheet but do not be deceived, the £41,285 BMW Z4M Coupe is a car with a mind – and a brief – all of its own.So instead look at it as being to the Roadster what the Porsche Cayman S is to the Boxster S – namely a hard-driving, no-nonsense machine for owners more concerned with the reactions of the machine than those from the pavement. Except it’s even more extreme, even than the Cayman.Power comes from the familiar 3.2-litre 343bhp straight six M3 engine and it’s still strong enough to hustle the 1495kg Bimmer to 62mph in 5sec flat. It’s true that, in this respect, it differs not at all from the Roadster and even its suspension, configured to include struts at the front and a multi-link rear axle appears very familiar. The devil, as ever, is in the detail.What’s it like?BMW figures that only die-hard enthusiasts will buy the Coupe which is why it has stiffened the springs, re-tuned the shockers, thickened the rear roll bar, quickened the steering and tweaked the diff to create a genuine road/track hybrid. Where the Roadster just understeers, the Coupe turns in savagely, drifts until its tyres will take no more and, thanks to double the torsional rigidity of the Roadster, has a level of poise and control its soft-top sister would not recognise.A Cayman slayer, then? Not really. The Z4M Coupe also comes with such a litany of faults – including a cramped cabin, terrible rearward visibility, poor ride quality and shoddy cabin materials that you’d need to be short, brave and unusually numb of backside to use it every day.Should I buy one?Only 200 will come to the UK each year, sales start in August and if you’re after a very flawed diamond then its appeal is unquestionable. After the M3CSL it’s the most sporting BMW of the modern era and that, for all its faults, makes it a mighty tempting proposition.