A few extra horses, a couple extra miles per gallon or a clutch of underserved consumers are always lurking out there, tempting those with the resolve and resources to go after them. For car brands, contentment is the kiss of death.

This makes the appointment of a new president at Jaguar Land Rover North America (JLR) an interesting study. Joachim (Joe) Eberhardt joins a company in ascendance, with its two brands having combined for 21% year-on-year-growth through November 2013. Adding a V6 option and all-wheel drive to its XF and XJ sedans – saying nothing of the introduction of the F-Type roadster – has helped goose Jaguar sales to the tune of 40% in that period. Tinkering with a proven formula might not typically figure on an incoming executive’s to-do list, but Eberhardt sees no choice.

“The future product portfolio will have to build on those successes,” he said in a telephone interview. “The first and most important thing, though, is that you’re authentic and faithful to your brand promise.”

Eberhardt re-enters the auto executive firmament after a few years out of the limelight. He previously held leadership positions at Mercedes-Benz and Chrysler, including some overlap when Daimler, Mercedes’s parent, operated as a merged company with Chrysler Group. It was under Eberhardt’s watch that Chrysler was purchased by a venture capital group, before its 2009 bankruptcy and 2010 purchase by Fiat Group.

Eberhardt said Mercedes offered a ready template for Jaguar Land Rover as it worked to broaden its North American footprint. “Way back when, Mercedes was not such a large part of the market,” he said. “I think our situation is quite similar.” To put the two companies’ positions in perspective, Mercedes-Benz USA will ship more than 300,000 units in 2013, while Jaguar will sell fewer than 20,000.

The British marque is indeed an outlier, but with new products in development such as a sport crossover based on the C-X17 Concept as well as a compact sedan, the brand’s product portfolio is expected to do some heavy lifting in coming years. The challenge, as Eberhardt sees it, is deepening the product offering without diluting what distinguishes Jaguar from its competitors.

“That otherness is one of the key differentiators,” he said. “That Britishness, that playfulness. You must be able to preserve that. And successful brands solve that conundrum effectively.”