Instructions
Turn on your PS2 and insert the "Gran Turismo 4" game disc into the unit. Wait for the game's main menu screen to appear.
Use the directional pad to scroll to the "Multiplayer" option in the main menu. Press the "X" button to select this option. You will be directed to the multiplayer setup screen.
Select the number of people who are playing from the list of options.
Plug in as many additional controllers as necessary into the ports on the front of the unit. The game will support up to four players.
Have everyone with a controller press "Start" to configure their controllers and start the game.