MAZDA is about to spring into action with the latest version of its iconic roadster.

The world's favourite sports car is about to get more refined and even better looking thanks to the addition of a retractable hardtop.

Costing a reasonable premium over the regular soft-top roadster, the foldable metal roof turns the MX-5 into a really handsome coupe without any real penalty.

And the new roof has the bonus of bringing theatre to the process of open-top motoring.

This new coupe-cum-cabriolet version of the MX-5 is called the RF with the initials standing for Retractable Fastback.

And there is no doubt that the roof is the star of the show. You don't even have to unlatch it manually to start it folding, you simply press a button and the motors do the rest. As long as you don't go above 6mph you can operate it when moving.

The mechanism and roof add 45kg to the weight of the car but you really don't feel the difference and the RF is every bit as agile and fun to drive as the roadster.

On sale from March 4, the MX-5 RF is priced from £22,195 and a special Launch Edition is available from £28,995.

For the extra cash the Launch Edition gives you Alcantara trim throughout the cabin, Recaro sports seats, special 17-inch BBS alloys, twin tone roof, piano black door mirrors and rear spoiler, a safety pack and a finish in either Soul Red or Machine Grey metallic paint.

In all the other models the cabin architecture and trim matches that of the roadster, so you get the same neat dash, controls and colour seven-inch display screen. The RF adds an additional smaller display on the instrument panel which gives trip readings, a compass bearing and a graphic of the roof when retracting.

Sat nav is standard on all RF models and you also get Internet connectivity for apps via your smartphone.

As with the roadster, the RF is powered by a choice of two SKYACTIV technology engines in 1.5 or 2.0-litre forms.

Both are coupled to a superb six-speed manual gearbox for maximum fun, although you can order the RF with an automatic transmission. It has to be mated with the larger engine and will cost about £2,000 over the standard cars.

The RF is thankfully just as good to drive as the roadster and the Sport Nav models have sports suspensions, Bilstein shock absorbers and a limited slip differential to boost your enjoyment.

Over testing country roads and across Dartmoor, the rear-wheel-drive RF was a delight, with the sprint to 60mph taking just 7.4 seconds - a mere 0.2 of a second slower than the roadster. Top speed actually increases by one mile per hour to 134mph with emissions of 161g/km.

The official combined fuel figure is 40.9mpg and I was able to better that despite pushing really hard.

The smaller 1.5-litre car was just as much fun. You have to work it hard to get the best from it but that just adds to the experience. It can reach 60mph in 8.4 seconds and is able to return an official 46.3mpg with emissions of 131g/km.

There is no doubt the steel, aluminium and plastic composite roof which takes 13 seconds to fold is the star of the show and its clever design means that boot space remains at 127 litres - enough for a couple of soft weekend cases.

With the roof up the RF cacoons you from our worst weather and drops to reveal speedster-like lines without impacting much on performance - a winning formula as far as I am concerned.

Mazda expect the RF will take up to 70 per cent of MX-5 sales with the large majority of customers also opting for the larger power plant.

Jeremy Thomson, managing director of Mazda UK told me: "We are very excited about the arrival of the RF. It adds a unique and stylish model to our range, one that stands distinct from the MX-5 convertible, yet retains all the award-winning driver appeal our sports car is famous for.

"With over 120,000 sales since its launch back in 1990, the UK has played a huge part in the MX-5 success and we expect the RF to continue that trend."