The M6 is powered by a 5.0-litre V10 with a monumental 500bhp. As you'd expect, it delivers blistering pace and pulls like a train, no matter what the situation. You can alter how the engine and gearbox react to throttle inputs, allowing you to vary between maximum acceleration or smoother progress around town. Uprated brakes mean the M6 stops as quickly as it goes.

You might think the M6 would be an out-and-out beast, but the use of lightweight materials and the excellence of its chassis give it an agile feel. It has an exhilarating drive thanks to phenomenal grip, razor-sharp handling and steering that's precise and full of feel. Yet, at the same time, the M6 is undemanding around town, and you can choose softer suspension settings for a more forgiving ride.

All the controls work with a slick, well-engineered action, and the noises the M6 makes are the kind you want. The V10 engine emits a purposeful rumble around town and a delicious growl when worked hard. The big tyres create some road noise, but the cabin is hushed at speed and there's little wind buffeting with the roof down.

You won’t get as large a discount on this model as you will on other versions in the range. Still, if you can afford to buy the M6, you can afford to run it, even if those pockets will have to be deep. High CO2 emissions mean big company car tax bills, and even if you match the sub-20mpg official fuel consumption (which is unlikely), you'll spend a lot of time at the fuel pumps. The M6 will hold its value reasonably well, but nowhere near as well as a Porsche 911.

The design of the M6's cabin is identical to other 6 Series models, but it's set apart by different materials, seats and details. It can't be faulted for quality or finish, but it doesn't feel as bespoke as the interior of something like an Aston Martin V8 Vantage. BMWs tend to be reliable, but there's a huge amount of complex electronics in the M6, and there have been reports of problems in the past.

The M6 comes with the same impressive array of safety features as other 6 Series models. Electronic systems help to maximise stopping power and keep you on the road to prevent an accident in the first place. Front and side airbags and pop-up roll-over hoops protect you should the worst happen, while an alarm, deadlocks and fully integrated stereo help to deter thieves.

Apart from some M badging, upgraded materials and a couple of extra switches, the view from the M6's driver's seat is much the same as in any 6 Series. That means the same fine driving position and wide range of adjustment – and the iDrive controller, which operates the sat-nav and more complex heating and stereo functions.

Like other 6 Series models, the M6 has four seats, but it’s a two-plus-two – and even then, only if the rear passengers are children: legroom is insufficient for adults, even for short journeys. At least the front two provide ample head- and legroom, while the boot is large and well shaped and will swallow a set of golf clubs and a week's holiday luggage.

The M6 convertible is expensive, even by BMW standards, but comes loaded with equipment. You'd expect features such as electric, heated front seats, full leather upholstery, climate control, parking sensors and a top-notch stereo, but maybe not the likes of a head-up information display, sat-nav and lights whose beam shines around corners. Among the very few options are a TV receiver and keyless entry.