What co2 car do you think would go faster?

im making a co2 car for ind. arts and we are racing them at the end so i dont know what design i should make it these 2 i thought looked pretty fast and simple to make. and we are making them out of wood. here are the 2 i was thinking about. http://web.westbloomfield.k12.mi.us/abbott/staff/maike/car1.jpg http://www.teamnebula.org/images/bullet%20car%20with%20wheels.jpg