A plug-in electric hybrid engine in the Audi e-tron concept is planned to be released for the by 2012 Audi A3 and the Audi A4 by 2020.

CEO Rupert Stadler talked about the concept and production projects for Audi during a recent Audi Press Conference. He said, "While we are planning small-scale series production for this car, which is a vital element in our innovation and technology plans, the electric driving experience will become a…