GameSpy: Gran Turismo 4 -- Everything We Know - Page 5

Gran Turismo 4's NEW CHEAT CODES, Discovered 19 Years Later!

Gran Turismo 4 Cheat Codes Uncovered Nearly 20 Years After Release

Gran Turismo 4 Cheat System demonstration (PS2)

Secret menu discovered in Gran Turismo 4 and Tourist Trophy : r/granturismo

Gran Turismo 4 codes discovered nearly 20 years later - Xfire

After 20 Years Cheat Codes Have Been Found For Gran Turismo 4

Gran Turismo 4 Loose Chase Camera

Secret Black Cars in Dealeships

Xenn's GT PSP Research Topic, Page 7

Gran Turismo 4 - Unlocking everything to give the player a head start in GT Mode