After winning a long battle for quality, South Korea's top automaker Hyundai Motor is focusing on beauty.

Hyundai, together with its affiliate Kia, was ranked the world's fourth largest carmaker in 2010 thanks partly to a decade-long drive to improve workmanship.

Now the firm sees its core competitive edge as good design, expressed in a 'fluidic sculpture' philosophy.

"We are now in the global top five and we needed a product that could reflect that, a product that could differentiate itself from other manufacturers," chief designer Oh Suk-Geun told reporters last week during a rare tour of the company's design centre.

"We felt the importance of a fluidic softness of line, and harmony in line can also mean a car is very aerodynamic."

The company says US sales rose around 20 percent annually over the past two years, with its salesmen attributing half of that increase to the look of the cars.

The new design concept was introduced in models released in 2010 and will gradually work its way through the whole line-up, through facelifts for existing models or new car launches.

In April Hyundai will showcase its new Santa Fe SUV at the New York motor show.

Oh said Koreans appear to have a talent for the job, making up a quarter of the design staff at one US automaker. But he says it's also important to give free rein to the 300 designers working in Korea. Some 200 more work overseas.

Hyundai sends designers on courses abroad and on refresher trips to destinations as diverse as Patagonia and Egypt.

"We send them to these countries with no particular assignment, but they come back with more ideas, more refreshed and create more value," Oh said.

The design facility is part of Hyundai's research and development centre covering 870 acres (350 hectares) at Namyang, south of Seoul in Gyeonggi province.

"Day to day, the biggest obstacle (to creativity) is the work environment," said Oh of the heavily industrialised surrounding region. "There's nothing too aesthetically stimulating in the surroundings."

So staff, he said, are free to go sketching outside the office, in a cafe or downtown, 'wherever they feel comfortable'.

Hyundai is the newest of the world's top automakers. Its first own-brand model was the boxy Pony in 1974 -- created with British manufacturing expertise, Italian design and a Japanese engine.

The Pony was also South Korea's first mass-produced car. Design is now a painstaking process involving freehand sketches, scale models, three-dimensional digital visualisation and a high-quality lifesize clay model.

The end result is kept highly confidential, with photography banned during last week's visit and cars swathed in dustsheets to hide them.

After applying its fluidic sculpture concept to create a family look, the company uses two radiator grille designs -- one hexagonal, one wing-shaped -- to distinguish between premium and less expensive models.

"As Hyundai expands to become a global brand, we need to make an emotional connection to our customers," said Casey Hyun, creative design manager. "Previously we did not have a consistent brand or identity.

"We need a distinctive family look but we need a design distinction between (market) segments."

Oh said the company will work towards a simpler and more refined design for future models and he was focusing on German carmakers. 'They are very good with aesthetics and the premium image that we are working towards'.

Hyundai's designers, he said, now tend to have the upper hand over engineers in conflicts over new models -- although engineers were also coming to appreciate the importance of looks in winning sales.

The disputes, he said, are 'part of a natural process of wanting to design something aesthetically beautiful'.