Renault design chief Laurens van den Acker isn’t always an easy man to interview, but he is always great value. Every bit as quirky and clever as the custom-made trainers he wears to every motor show, he is never anything but polite, but can still manage to deliver answers with such passion that his intensity occasionally borders on menacing.

To me, that hints at a man with a sense of conviction that lurks just beneath the surface, shrouded in impeccable manners but not about to be deviated from its course. I’d also argue that his strength of character is just as well, given where he’s taken Renault from since his arrival in 2009. Of course, he hasn’t achieved it all by himself, but today’s full reveal of the new Renault Megane is further proof of his team’s transformation.

Think back to his team’s designs that feel just so right today, led by a Clio that set the tone for other cheeky, characterful cars in the range, such as the Twingo, Captur and Kadjar. That front end is, in particular, a stroke of genius, working on every type and size of car they produce, and making a merit of the diamond logo that has previously caused so much trouble. Then, away from UK buyer’s eyes, the Talisman (nee Laguna) and Espace have taken a different, more grown-up direction that has clearly influenced the Megane today.

Several weeks ago I was fortunate enough to be given a sneak, under-embargo tour of the new Renault Megane. The very fact this was happening suggested an underlying confidence – and everything I saw backed that up. At the end of the day a clearly harassed van den Acker came to talk us around his car, and answer our questions.

What I loved was that he didn’t duck the marque’s deficiencies of years gone by – “This segment is the most competitive in the world. We’re going up against the very best - not just VW Golf, Ford Focus and Vauxhall Astra but also Audi A3, BMW 1 Series and Mercedes A-Class. We know we must up our game.” – nor did he pretend that he’d already answered questions that were hanging. “I cannot predict if customers will like our dual approach with the younger cars and the more grown-up cars," he said. "It is up to them if they buy it, and only time will prove if we have done the right thing.”

Now, with the Megane out in the open, there is a shrinking number of Renaults in the pipeline that van den Acker must recreate. Not that his work is done: the rest of the Megane family looks logical enough, but the rebirth of the Scenic as a more crossover than MPV-led vehicle is intriguing. Beyond that, there is the mooted range of Alpines to conceive and see through and, no doubt, other all-new cars to launch into all-new sectors, all the while keeping what he has started spinning along.

The only disappointment is that van den Acker’s brilliance is not being matched by the dynamics team. I guess all car companies must put their investment where they see the biggest returns, and Renault’s sales figures suggest they’ve backed the right side of the equation. In time, though, van den Acker’s design-led revolution must be matched by more complete, rounded vehicles. In the meantime, though, he should put his brightly trainered feet up for a brief moment and savour the success.