The Frankfurt Auto Show is ramping up its action a full week out of the first press days, and the latest to join the fray is the Fisker Surf concept. In this teaser image, we get an idea of what to expect, and it's good.

Fisker hasn't had a hard time generating the right curves and lines to get people interested in the Karma for reasons other than its green plug-in hybrid/range-extended powertrain, and from the looks of the Surf's preview sketch, it won't either.

Best of all, it looks to be wearing a shooting brake body style, making it the latest in the rebirth of the two-door sports wagon among high-end automakers. The current benchmark for the shooting brake realm is the Ferrari FF, and while we don't expect the Fisker Surf to approach the FF's performance levels, it should still be quick and luxurious--and of course, fuel efficient. The Karma, for instance, manages 408 horsepower, 5.8 seconds to 60 mph, 125 mph top speed, and 50 miles of all-electric driving before tapping into its gasoline onboard generator.

For more on the technology that's likely to underpin the Surf, check out our preview of the production Karma from last year's Paris Motor Show.