My video interview with Tesla's Franz von Holzhausen at the Detroit Auto Show.

Franz von Holzhausen, who came to Tesla Motors as design director from Mazda just a few months ago, arrived too late to help shape the battery-powered Tesla Roadster. The company has so far sold 160 of the $109,000 two-seat sports cars, a first step toward a goal of 1,200 a year.

Tesla is trying to diversify its lineup with the Model S, a more affordable ($59,900) five-passenger lithium-ion-powered sedan. The Model S project has been slowed as the company waits for some Department of Energy funding, but design work continues.

von Holzhausen may look like a very well-dressed surfer, but he certainly talks like a designer. “It’s going well and we’re 90 percent finished,” he said. “We have an opportunity with the Model S to refine the design language, the surfacing and all aspects of functionality.”

Even at $60,000, the Model S will find itself in flash company. von Holzhausen sees its competition as such pricey cars as the $114,000 Maserati Quattroporte and the $70,000 Mercedes CLS. “We’re looking for the early adopter who considers style to be an important part of the purchase decision,” said von Holzhausen. “But they’ll be getting a practical car with plenty of trunk space they can use for picking up building supplies at Home Depot.”

The Model S team is aiming for 300 miles of cruising range, which would be impressive in a luxury sedan that can achieve zero to 60 in five seconds. It should end up looking cool, too. The Model S will be on the market in 2011 if everything comes together.

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.