Haven't had the time to update this thread lately but I ran into something interesting:
Remember the Secret Settings menus from Gran Turismo HD Concept and GT5 Prologue? Remember how everyone thought GT5 scrapped the button code used to access it? Well, as it turns out, there has been a button code this whole time, hiding for so many years until I discovered it today.
Hold down these two buttons:
L1 + R1
And input this 13-button sequence to unlock it:
Up Up Up, Right Right Right, Up Up, Right Right, Up, Right, Start
...and there you have it; no save editing required to access the Secret Settings. Although you'll have to input the button code each time you want to make changes to the settings, as it doesn't stay unlocked when you exit the Options. Regardless, GT5 is the game that keeps on giving with each and every new discovery!
I plan on adding to the TCRF page with how to access the debug camera very soon. I'd recently lost my notes when I changed computers but @j0nny0093 still had a copy of them that I sent him, so I'll be getting to that as soon as I can.
This is a very good news, I'm planning to install HEN on my PS3 asap, so I can also get access to mod GT5 by myself. If you have any tips or updates let me know!