Audi in July launched the A6 E-Tron in standard and sporty S6 E-Tron guises, but still out testing is a high-performance RS 6 E-Tron flagship. The new RS 6 E-Tron has previously been spotted testing in its Sportback hatchback body style, but our latest shots show the car in its Avant wagon body style for the first time. Both body styles should be…