On 28 August 2009 GM/Opel presented the preliminary results of field tests for the HydroGen4 fuel cell vehicle at a press conference in Berlin.
Since December 2008, ten of Opel’s HydroGen4 vehicles have been driven for the Clean Energy Partnership. Nine major companies partnered with Opel to test the vehicles in everyday use.
The result: after 50,000 kilometres on the streets of Berlin, the fourth generation of GM/Opel fuel cell vehicles have proved that they can match the tough conditions faced in everyday operation. Hydrogen has also proven itself as a fuel for everyday use, according to the feedback from all the test partners. This field test gave GM and Opel important data that will help in further advancing technology towards the goal of assembly line-produced fuel-cell vehicles.

Please find the Opel press release :: here (German version only)