Select Campaign from the main menu and Double Driver campaign from the campaign menu. Load up any track and connect two controllers. In double driver mode, both players can control the car and make adjustments to speed, direction, etc. If you have another person with you, I reccomend this mode. It's a lot of fun racing together in one car, and the teamwork may actually help you get faster times. However, this can be done with one controller as well, since each controller has the potential to control all functions of the car.