The 2003 BMW M3 is available as a 2-door, 5-seat coupe. Starting at $54,500, the 2003 BMW M3 Convertible 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. The top of the line 2003BMWM3Coupe , priced at $ 46,500 , 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.