The 1999 Porsche 911 is available as a 2-door, 4-seat coupe. Starting at $65,030, the 1999 Porsche 911 (M6) RWD Coupe is powered by a 3.4L , 6 -cylinder engine mated to a manual transmission that returns an EPA estimated 17-mpg in the city and 25-mpg on the highway. The top of the line 1999Porsche911(A5) AWD Convertible , priced at $ 83,340 , is powered by a 3.4L , 6 - cylinder engine mated to a manual transmission that returns an EPA estimated