The 2005 Aston Martin DB9 is available as a 2-door, 4-seat coupe. Starting at $155,000, the 2005 Aston Martin DB9 Coupe is powered by a 6.0L , 12 -cylinder engine mated to a manual transmission that returns an EPA estimated 13-mpg in the city and 18-mpg on the highway. The top of the line 2005Aston MartinDB9Convertible , priced at $ 168,000 , is powered by a 6.0L , 12 - cylinder engine mated to a manual transmission that returns an EPA estimated 13-mpg in the city and 18-mpg on the highway.