 Just ten vehicles are believed to have been made; one drawback was that due to the extra weight of the electric drive, the vehicles were less efficient when running on their engines alone than standard Audi 100s with the same engine.Two years later, Audi, unveiled the second duo generation, the Audi 100 Duo – likewise based on the Audi 100 Avant quattro.Once again, this featured an electric motor, a three-phase machine, driving the rear roadwheels.