The range-topping M6 is powered by a storming 507bhp 5.0-litre V10. There's also a 367bhp 4.8 V8, a 258bhp 3.0 six-cylinder unit and a 3.0-litre twin-turbo diesel with 282bhp. Even the smallest petrol engine, the 630i, serves up 221lb ft of pull and delivers strong low and mid-range urge, blasting you to 60mph in under 7sec on its way to a top speed of 155mph.

The 6 Series is the sort of car that can put a country behind it in a day or serve up a great drive on a twisting road and leave you feeling fresh. And it rides well, even on optional 19-inch wheels. It has boundless electronic driver aids to control brakes, traction, throttle, gearshift patterns and even steering.

Blip the throttle of the 650i and it sounds like a military uprising from outside the car. Inside, there's just a muted gurgle, and even that disappears when you are cruising, although on the 19-inch wheels there is some road noise. The 3.0-litre car is equally refined, while the M6 howls gloriously under acceleration but is otherwise quiet. The diesel is a bit noisier than the petrol models, but it makes a sporting thrum rather than an unpleasant clatter.

Although the 4.8 V8 is efficient for its size, running costs are going to be high. The 630i offers better fuel economy and a drop in company car tax over the V8, but if it's fuel economy you're after, then the 635d is the best bet - it returns over 39.2mpg. The car will be pretty rare in the UK, which might help resale values.

Adopting much of the style and materials of the 5 Series on which it is based makes this car look, feel and smell expensive, even if it doesn’t have the warmth of a Jaguar XK or a Maserati. Mechanical reliability holds no fears, but some of BMW’s latest electronics can go wrong.

A comprehensive selection of active driver aids and passive safety protection is fitted as standard, and there’s even more on the options list, so it’s fair to say the car looks after its occupants well. With BMW’s security record, it should be well defended against thieves, too.

Few drivers are likely to have difficulty adjusting the wheel and pedals to their preferred position, or to complain about the room afforded them. What they might struggle with is judging the front and rear of the car in tight manoeuvres, or the iDrive rotary control that works the climate, stereo, navigation and phone systems (although the latest version is far better than the original).

The 6 Series is a two-plus-two, but only if the rear passengers are children: legroom is insufficient for adults, even for short journeys. The boot will still take two sets of golf clubs even when the roof is folded.

The list of standard equipment is everything you’d expect to find in a £50,000-plus sports convertible, but you can send your invoice rocketing with the options list. Additional electronic driver aids, voice-activated iDrive controls, bigger wheels and tyres, sat-nav and even a head-up instrument display on the screen are all available.