The 2006 Audi A4 is available as a 4-door, 5-seat sedan. Starting at $37,340, the 2006 Audi A4 FrontTrak FrontTrak Cabriolet is powered by a 1.8L, 4-cylinder engine mated to an automatic transmission that returns an EPA estimated 23-mpg in the city and 30-mpg on the highway. The top of the line 2006 Audi A4 3.2 FrontTrak FrontTrak Sedan, priced at $34,490, is powered by a 3.1L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 21-mpg in the city and 29-mpg on the highway.