The 2005 BMW M3 is available as a 2-door, 5-seat coupe. Starting at $47,300, the 2005 BMW M3 Coupe is powered by a 3.2L , 6 -cylinder engine mated to a manual transmission that returns an EPA estimated 16-mpg in the city and 24-mpg on the highway. The top of the line 2005BMWM3Convertible , priced at $ 55,800 , is powered by a 3.2L , 6 - cylinder engine mated to a manual transmission that returns an EPA estimated 16-mpg in the city and 23-mpg on the highway.