From GTPlanet Game Guides

Gran Turismo 4 is the last PS2 edition of the famed driving simulator from SONY Computer Entertainment and Polyphony Digital. It boasts over 700 vehicles from the historic 1886 Benz Patent Motor Car and 1915 Model T to modern-day supercars and Le Mans racers. The number of tracks is equally impressive. There are over 80 locations including the highly dangerous and technical Nürburgring Nordschleife and the home of the 24 Hours of Le Mans: Circuit de la Sarthe.

• Car Lists
• Car Settings
• Cheat Codes
• Drifting
• FAQs
• Hardware List
• Licence Tests
• Prize Cars
• Race Database
• Race Reports
• Screenshots
• Soundtrack
• Track List
• Tuning
• Videos

The GT4 Section of the forum can be found [here].