BMW 6 Series convertible (2011-2018)

BMW's 6 Series Convertible has lost many of it's quirky exterior design cues in place of a smoother appearance and an impressive range of very high-tech features. Facing stiff competition in the form of the Jaguar F-Type convertible and Mercedes-Benz SL-Class, the new 6 Series features an improved head-up display system that projects vital information onto the driver's windscreen. Thanks to a longer and wider body the stylish cabin is now also very spacious compared to the previouls model although rear seats are best suited to small adults or children.

Driving the 6 Series is an involving experience but requires careful placement on narrow UK roads due to it's overall size, for long distance cruising however, it's hard to beat. Available with two turbocharged petrol engines in either 4.4-litre, eight cylinder or 3.0-litre, six cylinder layout, the new 6 Series Convertible is also available with a more frugal turbocharged diesel. Capable of 0-62mph in 5.5 seconds, the petrol engined 640i is effortlessly fast but also returns an impressive 37.2mpg at the fuel pumps.

With the stylish new 6 Series, BMW has incorporated added practicality to their high profile drop-top whilst maintaining strong performance and reduced emissions.

The diesel 640d SE Convertible manages 52.3mpg which is very impressive for this type of car and with emissions of only 149g/km of CO2, will cost only £130 per year to tax. Petrol 640i and 650i models are much thirstier achieving 37.2 and 31.7mpg on the combined cycle and attract tax bills of £225 and £290 respectively. Servicing is not cheap for the larger engined models either, with tyres and consumables all commanding higher prices than average. CO2 emissions can vary depending on the size of the car's wheels, so bear this in mind if the annual tax bill is an important consideration - some cars may fall into pricier brackets.

BMW is famous for building cars that are rewarding to drive. The latest 6 Series soft-top is no exception. Improvements to chassis stiffness mean the car remains stable over mid-corner bumps handling almost all road surfaces in the same composed, grippy way, the total lack of body roll highlighting the sophisticated suspension setup.

Engines are wonderfully strong, with the 310bhp 640d being the surprise candidate, capable of sprinting from 0-62mph in 5.5 seconds - the same as the 320bhp petrol 640i. The eight-speed automatic gearbox is slick with many shifts happenning seamlessly and although all 6-Series models allow the driver to pick from three driving modes (Normal, Sport and Sport+), optional Adaptive Drive lets keen drivers fine-tune the suspension, engine, steering, traction control and gearbox.

Ride quality is excellent, the body remaining composed over lots of different tarmac surfaces, even handling pot holes with surprising ease. Inside, the larger cabin allows passengers more head and legroom and is a welcome improvement over the previous model, easily remaining competitive for comfort. All materials used are of high quality, including the sumptuous leather seats used throughout the range.

An area where BMW has made noticeable improvements over the previous model, the 6 Series Convertible still struggles to carry four adults in comfort even though the rear seats are more spacious. Access to the back seats isn't easy with roof up either. The useful 350-litre boot however is large enough to carry golf clubs and small suitcases, making it a more practical choice than sportier cars such as the Porsche 911 or Audi R8.

Previous 6 Series models sold in huge numbers and achieved very high reliability records. BMW's highly developed engines are unlikely to cause any trouble if cared for properly.

The 6 Series is very expensive to buy but comes loaded with high-tech gadgets and gizmos. The 640i M Sport Convertible comes with voice activated sat nav, Bluetooth, heated front seats, sports steering wheel, parking sensors and an eight-speed automatic gearbox. You can also lock or unlock its doors, flash its headlights and even set its ventilation from your smartphone using BMW's 'remote services'. Interior's are classy and stylish with electronic everything, including an optional Wi-Fi hotspot and wireless phone charging. Options are pricey thoiugh, the excellent head-up display costs an extra £980 and selecting the highly advanced Adaptive Drive system adds £3,400 to the asking price.