The Audi R8 [4] ( Typ 42 ) [6] is a mid-engine , 2-seater sports car , [4] [7] which uses Audi's trademark quattro permanent all-wheel drive system. [4] [8] It was introduced by the German automaker Audi AG in 2006. [...] R8 e-tron The Audi e-tron concept car was unveiled at