After more than a year in development, Fisker Automotive unveiled the vehicle it plans to start making by the end of 2009. If the company stays on track, it would beat 2010 expectations for General Motors Corp.'s Chevrolet Volt and Saturn plug-in Vue as well as a plug-in hybrid from Toyota Motor Corp.The stakes are high for any automaker trying to deliver a lithium-hybrid plug-in vehicle. Lithium-ion technology, while promising, presents safety challenges as developers test various chemical combinations and software programs to keep the batteries from overheating.Recently, Fisker unveiled a muscular four-door sports sedan -- called the Karma -- the same day that it announced a multimillion-dollar investment from venture capital firm Kleiner Perkins Caufield & Byers, which counts Al Gore as a partner.Fisker Automotive's vehicle is billed to drive 620 miles, with the first 50 miles coming from a battery that can be charged in a household outlet. After that, an onboard gas-powered generator charges the battery. The Karma is expected to reach 60 m.p.h. in 6 seconds and have a top speed of 125 m.p.h.