Official Word:

Shortly after the successful market launch of the S400 HYBRID, currently the most fuel-efficient luxury-segment sedan with a gasoline engine, Mercedes-Benz will be presenting the first "three-liter car" in the premium segment - the Vision S500 Plug-in HYBRID - at the 63rd IAA in Frankfurt. The technology vehicle will display the future of Mercedes-Benz' modular set of hybrid systems. The Vision S500 Plug-in HYBRID can drive for up to 18 miles solely on electric drive and...Read.