When Mazda dropped the bombshell announcement that its hugely talented and youthful design boss Laurens van den Acker was leaving to "pursue other interests", the global car-design network went into gossip-overdrive.

During his three years at Mazda, Dutch-born van den Acker had overseen the creation of a series of brilliant, breakthrough concept cars that transformed the car maker into the hottest design-led automotive brand on the planet.

So potent was the collective creative force of his Nagare, Kabura, Senku, Ryuga and Sassou concepts, van den Acker had become the must-have target for car industry headhunters worldwide. Now, it seemed, one of them had claimed the prize scalp.

Soon after Mazda announced that he was leaving, rumour spread that van den Acker would succeed the influential Patrick le Quement at Renault. Three days later, Renault confirmed that the pundits had got it right.

But why would Laurens van den Acker - a true cosmopolitan who was in the process of adding Japanese to his fluent Dutch, German, Italian and English - jump ship from his relative comfort zone at Mazda, where he'd clearly had the freedom and influence to generate a genuinely new design language? What's more, he doesn't (yet) speak French fluently.

What made his departure from Mazda even more ironic was the fact that the first van den Acker-inspired production car - the next-gen Premacy/5 MPV - was still more than a year away.

"I was very happy at Mazda and had no intention to leave," van den Acker told me days after his switch to Renault had been confirmed. "As you know, I was probably having too much fun. The design team is fantastic and with Nagare [Japanese for 'flow'] we managed to set a strong new direction that we were busy turning into a production reality."

Van den Acker moves to Renault as Design Director, reporting to Chief Operating Officer, Patrick Pelata. It's a senior role that's clearly a step up from his old position as General Manager of Mazda Design, responsible to the head of R&D.

Neither his new status nor the fact that Renault outsells Mazda roughly two-to-one worldwide (2.4 million vs 1.3 million last year) was critical to his decision, according to van den Acker, who seems much younger than his 44 years.

"When Renault approached me, I couldn't be anything else but very honoured to be given this unique opportunity and responsibility," he said. "Patrick le Quement is one of the most pre-eminent car designers in the world, and the reputation of Renault Design is unparalleled. I considered this a once-in-a-lifetime opportunity."

If his answer is predictable, it's also clear that he means it and is genuinely sorry to leave Japan, a country he describes as "the most fascinating in which I've ever lived".

"I am strengthened, though, by the thought that with Maeda-san [his successor at Mazda, Ikuo Maeda, who styled the RX-8 and new Mazda 2], Mazda Design is left in very capable and experienced hands." he said. "I have no doubt that Mazda will continue its momentum. I wish them well and I will root for them."

Significantly, van den Acker heads to a Renault that has recently shifted away from its often-controversial style leadership. Instead, it's embracing a strategy that puts more emphasis on quality than bold design. Insiders say Renault believed that by plucking a high-profile outsider from a design-led Japanese car maker - where quality is taken for granted - it could simultaneously achieve both its aims.

Perhaps understandably, when I spoke with him pre-Wheels deadline, Laurens couldn't yet comment about that. "I'm not yet in a position to give you a good idea of what the challenges will be," he told me. (Although he joined Renault on May 15, he doesn't officially take over from le Quement until October.)

Late last year the likeable van den Acker gave Aussie hacks a long-lead preview of the new Mazda 3 and explained the theory behind the radical look, known internally as Flow Design. Through a welcome smile and obvious enthusiasm, he explained to Wheels that Flow is a surface treatment which implies air or fluid flowing over a car's textured surfaces to play with the light. As the various concepts prove, the surfaces vary depending upon the vehicle type and its shape and personality. Mazda's more traditional design elements, like the five-point grille, the (much-copied) prominent front wheelarches and the head and tail-light treatments, plus the fast-wedge body shape, are also important elements. And there is a visual connection between all these elements so that the design flows.

"We can apply Flow to any Mazda," van den Acker claimed. "Trucks, sports cars, sedans ... everything, because the look has depth and is culturally simple to understand, though the execution demands incredible attention to detail."

Always, there is a sense that what drives Flow Design is a desire for good-looking cars.

"If we lose beauty in the process, what is the point? We are going to have the efficiency, a low aero and light weight, but, guess what ... we are going to be beautiful, too.

"We have embraced and been inspired by nature; the promise of the outside must be sustained by the interior. Too many cars today look like industrial products and owe their inspiration to electrical goods.

"What has been surprising is that when you do something advanced you expect it to be an acquired taste, even provocative, but people seem to naturally embrace the look ... though, yes, we still have to prove it [on production cars]. We want Mazdas to be instantly recognisable designs, so that you could take a picture from any point and know it's a Mazda. And we want to get it out quickly so that we own it. Otherwise, the Chinese will do it."

Robert Cumberford is a former designer who, among other car makers, worked for Renault in the 1970s. He's now the world's leading independent car design pundit. Cumberford believes that under van den Acker, Mazda has shown the world that it's possible to embrace Japanese cultural sensibilities - with a sense of motion and emotion that are "central to the global love of cars" - to express a true Japanese automotive character.

"It was never my goal to show Japanese design," Laurens said. "You could live [in Japan] for 20 years and still not understand the culture. I just wanted to make good Mazdas and didn't care where the inspiration came from. Now people say they look Oriental. A Japanese designer could say that; I can't."

Laurens began his design career at Design Systems, a consultancy in Turin, Italy, after graduating from the Netherlands' Delft University with a Masters in Engineering from the Faculty of Industrial Design. The tall Dutchman, born in the Netherlands though he has since lived in six countries, says the cars that most influenced him as a student were the General Motors Firebirds I, II and III and the wild Bertone BATs 5, 7 and 9, all concepts from the 1950s.

Current Ford design boss J Mays first met van den Acker when they both worked for Audi in the early '90s. Mays then poached the talented Dutchman, first to Arizona-based brand development company SHR Perceptual Management, and later to Ford.

Before he moved to Mazda in early 2006 (succeeding Scot Moray Callum), van den Acker worked for Ford in Dearborn. He was involved in creating such concepts as the Ford 427, Model U, Bronco, GloCar, MA and 24/7 - "I've done my share of wacky cars," he says - as well as the Ford Escape and Mercury Mariner production cars.

Away from cars, he's perhaps most famous for his seemingly endless supply of colourful sneakers. True to his convictions, he wore a pair to the interview with Renault's Pelata. Mazda people tell of how he wore a different pair for eight consecutive days during a press event. How many does he have? "As many as my wife," he says. "These things are secret, but I do wear a different pair every day."

Says Cumberford, "Laurens was an excellent choice for what is a very important design job; certainly better than any of the others I know were in the running.

"The hardest part of being chief designer anywhere is getting past the need on the part of untutored executives to put their hands on the product to show how powerful they are. Jacques Calvet [who ran PSA Peugeot/Citroén from 1983 to 1997] almost destroyed Citroén with his conservative tastes. Laurens will need tremendous strength of character and self-assurance in this job."

On my reading a design revival is a near certainty at Renault, given van den Acker's impressive record, as a designer and a manager.