BRITAIN’S best-selling convertible takes a leap forward next week with the official sales launch of the bigger new MINI Convertible.

With major refinements against its predecessor, the car features a striking new design and significant enhancements to make open-topped MINI motoring even more dynamic, stylish and practical.

On sale in the UK from March 2016, it follows hugely successful model launches in 2004 and 2009. Between 2011 and 2015, 29,415 MINI Convertible models were sold in the UK making it the best-selling convertible in the country.

It remains the only premium soft-top four-seater convertible in the small car segment, and the UK continues to be the largest market worldwide for the new MINI Convertible.

New features include a fully electric roof that is quieter and smoother than the previous model, a fully integrated rollover protection system and more rear space than ever before.

The new cars are bigger: The all-new MINI Cooper Convertible and Cooper D Convertible are 3,821 mm long, with the MINI Cooper S Convertible 3,850 mm and the MINI John Cooper Works Convertible 3,874 mm long. All models are 1,727 mm wide, 1,415 mm high and have a wheelbase of 2,495 mm.

Those dimensions have increased compared with the outgoing model, with 98 mm extra length, 44 mm extra width and 1 mm extra height. The wheelbase is 28 mm longer and track width has also grown a further 42 mm at the front and 34 mm at the rear.

The increase in dimensions has enhanced comfort levels and freedom of movement in all four seats. The two front seats have a wider range of adjustment, while rear passengers benefit from easier access, more headroom, a longer seat surface and improved lateral support with the two individual seats.

Smart design and interior packaging means luggage volume has expanded by around 25 per cent to 215 litres with the roof closed and 160 litres with it folded down.

A high level of standard equipment across the range includes MINI Visual Boost Radio with a 6.5-inch screen, MINI Connected, Bluetooth connectivity with USB audio, Rear Parking Distance Control and a Reversing Camera.

Options include an industry-first Union Jack design woven into the MINI Yours fabric roof. There are two new exterior colours – Caribbean Aqua and Melting Silver – with a new Chester leather in Malt Brown available for the interior.

A four-car range will be available from launch – the MINI Cooper Convertible, MINI Cooper D Convertible, MINI Cooper S Convertible and the MINI John Cooper Works Convertible – with three petrol engines and one diesel. On-the-road pricing starts from £18,475.

Fully electric, the roof of the new MINI Convertible is suitable for year-round use and has been optimised for the very best heat and acoustic insulation. Quieter than ever before, when opened it folds neatly behind the rear seats. The front roof section can also be retracted by up to 40 cm, and this can be carried out at any speed.

For a quick reaction to sudden changes in the weather, the soft-top can be opened and closed at speeds of up to 18 mph. The two operations are activated by means of a toggle switch on the front roof frame. When the vehicle is stationary, it can also be operated using a button on the remote key. Both operations take just 18 seconds.

Safety is a critical consideration in open-topped cars and the new MINI Convertible includes new integrated rollover protection which extends automatically when required.

Customers wishing to add extra spice to their MINI Convertible can choose to add a Chili pack to their car. Containing some of the most popular optional extras, such as LED headlights and daytime running lights, Interior lighting pack, Automatic dual-zone air conditioning, cruise control, MINI Excitement pack and much more, Chili pack helps MINI Convertible customers to get more MINI for their money.

A new feature incorporated into MINI Connected XL, developed especially for the MINI Convertible, is the ‘rain warner’ function. If the vehicle is parked with the roof open and the forecast is bad, the driver is sent a message via their smartphone suggesting that it might be time to close up.

If the MINI Convertible is being driven and there is rain forecast ahead, the driver will be alerted on the centre console. Additionally, if the car is travelling over 30 mph, MINI Connected XL will suggest possible places to pull over and close the roof.