The 2004 Pontiac Grand Prix is available as a 4-door, 5-seat sedan. Starting at $22,415, the 2004 Pontiac Grand Prix GT1 is powered by a 3.8L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 20-mpg in the city and 30-mpg on the highway. The top of the line 2004 Pontiac Grand Prix GT2, priced at $24,315, is powered by a 3.8L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 20-mpg in the city and 30-mpg on the highway.