The 2008 Audi A6 is available as a 4-door, 5-seat sedan. Starting at $42,950, the 2008 Audi A6 FrontTrak FrontTrak Sedan is powered by a 3.1L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 27-mpg on the highway. The top of the line 2008 Audi A6 4.2 quattro Sedan, priced at $56,300, is powered by a 4.2L, 8-cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 23-mpg on the highway.