A truly world-class luxury automaker needs a performance brand. Mercedes-Benz has AMG, BMW has its M division, Audi's Quattro GmbH produces an RS line, Lexus has taken to bestowing its performance-oriented models with the letter F, Cadillac uses the letter V, and Jaguar has R and R-S. But Infiniti has been trying to catch up with the rest of the pack for several years now.

The Japanese luxury automaker started the Infiniti Performance Line in 2010, but in the years since it has only produced two models — and they were both based on the Q60 (or the two-door version of the G37, as it was known then). Thankfully, Infiniti finally turned a new page with the unveiling of their Q50 Eau Rouge at the Detroit Auto Show this year.

If you have even a cursory understanding of French, you'll probably be wondering why Infiniti named its new performance sedan concept “red water” — but that's not from where it derives its name. Eau Rouge is the name of the most challenging corners at one of the most legendary racetracks in the world, Spa Francorchamps (home of the Belgian Grand Prix). Evoking the name draws on the auto brand's ever-deepening partnership with Red Bull Racing, the team that's heading into the 2014 season as the reigning Formula One World Champions for the fourth year in a row.

There's more to the Eau Rouge concept, however, than a name. Although the show car may look mostly like the Q50 sedan you can buy at your local Infiniti dealer, the company's engineers have replaced most of the body panels with carbon fiber. In fact, only the front doors and part of the roof were left unchanged.

"From our shared passion for performance with Infiniti Red Bull Racing grew a collective desire to produce an ambitious and powerful Infiniti Q50 design study," said Infiniti design chief Alfonso Albaisa. "The overall design creates a feeling of refined muscularity."

The lightweight composite body panels give it a wider, more aggressive stance, punctuated by very serious-looking aerodynamic elements and 21-inch wheels at each corner — all of which betray a far more potent engine under the hood than the 328hp, 3.7-liter V6 that comes stock.

So what, exactly, is under the hood? Infiniti isn't saying, probably because like most concept cars, the Eau Rouge design doesn't actually have an engine. At least not for any purpose other than moving it on and off the show stage. Rest assured though, because Infiniti is talking seriously about putting it into production. "If we built this car I would expect it to feature over 500 horsepower and 600 pound-feet of torque," said Infiniti's President Johan de Nysschen. "The engine we are evaluating for the Q50 Eau Rouge is a big personality, V-cylinder engine with forced induction."

That sounds very promising indeed, but word has it that the Q50 wouldn't be the only one to get such an athletic makeover. The same formula could be applied across the company's line-up, giving the Europeans a run for their money and Infiniti something to bridge the gap between the luxury automobiles it is known for making and the racing cars it sponsors.