Mike Litt , Consumer Program Advocate, U.S. PIRG, speaks with  Elisabeth Caspari and Marcus Moench during a press conference outside of the Volkswagen headquarters after trying to return their 2010 Volkswagen in Herndon, Va on Jan 19, 2016. Marcus and Elisabeth own one of the 567,000 diesel vehicles in the U.S. that Volkswagen sold as &quot;clean&quot; but was secretly designed with a &quot;defeat device&quot; to emit as much as 40 times the legal limit for smog-forming pollutants.  Photo by Kris Connor