A Mercedes S500 Plug-In Hybrid car is pictured as a world premiere during a media preview day at the Frankfurt Motor Show (IAA) September 10, 2013. The world's biggest auto show is open to the public ... more 
A Mercedes S500 Plug-In Hybrid car is pictured as a world premiere during a media preview day at the Frankfurt Motor Show (IAA) September 10, 2013. The world's biggest auto show is open to the public September 14 -22. REUTERS/Kai Pfaffenbach (GERMANY - Tags: BUSINESS TRANSPORT) less 
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Reuters | Photo By KAI PFAFFENBACH / REUTERS
Tue, Sep 10, 2013 5:22 AM EDT