Five months after debuting its Karma plug-in hybrid car at the Detroit auto show, Fisker Automotive has already hit the track with a test mule in Southern California, Autopia reports. Apparently the company is serious about going after the Tesla sports car (and not just in court) with its own four-door version, which will sell for $80k ($20k less than the Tesla) and is slated for production next year.

Fisker isn't saying anything about what's under the hood of the prototype, the report said. But they "do know the company is working with Quantum Technologies on a series parallel drivetrain that will use an electric motor to drive the wheels and an internal combustion engine to charge the lithium-ion batteries. Autocar says it could be a 1.4 liter Volkswagen engine."

All Henrik Fisker would say, through a spokesman to Autopia, is that the car just might end up with a German engine.