Performance nutters may grouse but car manufacturers can't really deny the high-efficiency end of the automotive market. For September's Frankfurt Motor Show, each of the German heavy hitters pulled out a lightweight and super efficient concept and in Audi's case it was both coupe and spyder version of the Audi Urban Concept. That Audi wasn't the only Volkswagen Group brand exhibiting such a car in Frankfurt likely suggested that the group as a whole was considering some sort of sub-MQB and sub Up! platform for these little city cars. Further, recent intel from various sources including CAR Magazine's Georg Kacher suggest Audi will build a limited run of the little car in series production.