The 2007 Audi S4 is available as a 4-door, 5-seat sedan. Starting at $48,500, the 2007 Audi S4 (M6) quattro Station Wagon w/o Heated Seats is powered by a 4.2L, 8-cylinder engine mated to a manual transmission that returns an EPA estimated 15-mpg in the city and 21-mpg on the highway. The top of the line 2007 Audi S4 (A6) quattro Sedan w/o Heated Seats, priced at $48,700, is powered by a 4.2L, 8-cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 23-mpg on the highway.