While the rise of the premium brands seems to have defined the changing dynamics of the car industry in the last decade, the growth in stature of the value brands is a more remarkable story. Hyundai and Kia in particular.

It’s much harder to grow a brand upwards from a budget baseline than it is for a brand to apply premium qualities to more functional vehicles as BMW, Mercedes and Audi have done. And Hyundai and Kia have done it without the resources of an existing group.

The Korean group has experienced phenomenal growth, with a doubling of European sales since 2008. Both brands have reeled customers in with competitive pricing and long warranties, and it’s easy to understand why the value brands have prospered in the years since economic meltdown.

But it’s not all about value. In a visionary move, in 2006 Kia recruited the European designer of the iconic Audi TT to head its styling. He’s since become the boss of all Hyundai-Kia design and the most senior non-Korean in its business globally. In so doing the management has elevated the brands and created a compelling combination of the rational and emotional. They now effectively offer what Toyota did a decade ago – reliable, hassle-free motoring for ordinary consumers – but with added style. And remarkably they’ve now comfortably overtaken the Japanese giant in Europe: Hyundai’s market share this year is 3.5% and steady, Toyota’s 4.0% and falling. Kia’s is 2.8% and climbing, giving the pair a combined 6.3% of the market, 50% more than Toyota.

And now Hyundai has become one of the world’s 50 most valuable brands according to the Interbrand Best 100 Global Brands index. To put that in perspective, we’re talking companies in all sectors. Companies like Coca-Cola, Google and Apple. Hyundai’s rank is 43, putting it ahead of Sony, Facebook and Heinz.

In automotive terms it’s just one place behind Ford at 42. It’s seventh out of all automotive manufacturers, with Toyota, Mercedes, BMW, Honda and VW the only other brands to beat it. Over the last five years Hyundai’s brand value has grown 96%, mirroring sales.

Like sister brand Kia and Skoda, Hyundai now wants to sell its cars more on quality and less on value. It wants to raise perception and prices, to create more profit. But like the premium brands moving into mainstream territory it faces the possibility of losing some its brand relevance. Unlike the premium brands however, when the value brands move towards the mainstream they risk becoming merely part of the squeezed middle to which they currently offer such an appealing alternative.

Hyundai’s challenge now is to grow sustainably: to retain brand differentiation and to nurture a strong enough brand personality to avoid joining the mainstream.