EVERY so often a car comes along that changes your whole perception of a brand. The Fiat 500 did it with its retro styling, and so, too, did Citroen’s DS3, which gushed flair and imaginative styling.

Now Citroen is asking the question again: Why conform?

This time the acclaimed DS line is breaking new ground with the arrival of the DS4, which redefines expectations of a mid-size coupé with its blend of bold design, elegance and versatility.

The second model in the DS line, the DS4 has already been voted Most Beautiful Car of the Year by more than 60,000 web users in 62 countries.

Designed first and foremost as a sleek coupé, but with five-door flexibility and a raised stance, it might well be described as a perfect sequel to the DS3.

Its eye-catching lines are enhanced by a chrome-finished waistline and dark tinted windows.

Sculpted wheel arches emphasise the alloy wheels, while the running lights introduced on the DS3 ensure that DS4 stands out from the crowd.

Inside you will find a surprisingly spacious cabin offering three fullsize rear seats. But before you enter, it is worth looking at the seamlessly integrated rear doors with handles encased in the car’s extended window frames.

The wow factor is undeniable. The sophisticated and beautifully appointed cabin offers exquisite comfort in a premium environment.

You will struggle to find a better cabin on four wheels for anything less than twice the price.

The interior exudes a sense of innovation and finesse through attention to detail. From the excellent acoustics to the cabin materials, the DS4 oozes sophistication.

Cast your eyes anywhere and you cannot fail to be impressed. The drilled aluminium pedals, embossed door handles and a choice of five leather combinations all play their part in producing an opulent atmosphere.

Despite the abundance of features and roominess of the cabin, the DS4 measures only 4.27m long, 1.81m wide and 1.53m high.

There is room to seat five adults in comfort with decent head, leg and shoulder room throughout. A 359- litre boot increases to 385 litres, using the under-floor storage and the interior is home to a range of clever storage solutions.

Citroen has really gone the extra mile to provide an excellent audio system and serene onboard atmosphere is created by soundproofing comparable to models segment above.

The deeper you dig, the more you find, and during my week-long test I discovered opportunities to personalise the onboard ambience with a range of polyphonic sound themes and change the colour of the dials and the instrument cluster.

Additional premium touches such as massaging front seats with electric lumbar adjustment, an advanced audio system and Citroen’s integrated eMyWay navigation, entertainment and communication system are also available.

The DS4 is powered by a range of five Euro 5 compliant engines. There are two diesels – HDi 110 and HDi 160 – and three petrol units that were co-developed with BMW – VTi 120, THP 155 and a new THP 200.

The spirited THP 200 dispenses power and performance with a top speed of 146mph and 0-62mph time of 8.5 seconds, yet still achieve an average 44.1mpg and CO2 emissions of 149g/km.

The HDi 110 is also available as an e-HDi version. Citroën’s innovative micro-hybrid technology, with second generation Stop & Start, boosts fuel economy by up to 15 per cent in city driving conditions and lowers the model’s official CO2 emissions to just 114g/km. Sales of 70 per cent diesel and 30 per cent petrol are anticipated.

Engineered to be highly responsive, DS4 is sporty and fun, yet smooth and comfortable.

Citroën has built upon its expertise in creating the most civilised suspension set-ups and also the recent experience in the development of DS3. The way in which the steering responds to inputs and the suspension keeps the body in check when cornering is impressive. While it will never match the sprightliness of the smaller DS3, for a car of its size and status the DS4 is an enjoyable car to drive in a variety of conditions.

The torquey, flexible nature of the high output diesel version is ideally suited to the DS4’s multi-faceted personality. It will cruise with ease and potter through urban traffic quite happily, but should you be fortunate to find yourself on an open road it will punch to 62mph from rest in under ten seconds. The headline figures of 55.4mpg and 134g/km of C02 should mean it makes financial sense too.

One of the safest vehicles in its class, the DS4 features, as standard, ESP with intelligent traction control, ABS with EBD and EBA and six airbags.

It is available in three trim levels – DSign, DStyle and DSport. Prices start at £18,150 for the VTi 120 DSign, rising to just under £24,000 for the range-topping THP 200 and HDi 160 DSport versions.

CITROEN DS4 Dstyle Hdi 160, FROM £22,950

PRICE: DS4 range from £18,150.

ENGINE: Two-litre diesel.

TRANSMISSION: Transmission: Six-speed manual.

PERFORMANCE: 0 to 62mph in 9.3 seconds; top speed 132mph.

ECONOMY: 55.4mpg combined.

CO2 RATING: 134 g/km.