I don't suppose the thread moderation is selective? i.e. the "old timers" who know what we're on about would be let through? Not sure if the programming can support it.. Just a thought, no biggie (since any decent thread will be allowed through easily enough).
As for sub-forums, here's what I'd suggest:
Cars (screencaps, general discussion, etc)
Tracks (screencaps, general discussion, laptimes, etc)
Settings (xxx car on xxx track, etc)
Drifting
Online (which would also include the standard Weekly Races from the current "Online" forum, which I think should still exist for those of us who don't play online).
Races & Licenses (where folks can discuss specific Missions, Licenses, etc.. after a few months, the "Licenses" name could probably be removed from the forum title, although it would still be the place to talk about it).
General GT4 Discussion
The reason I mention separate car/track forums is because this game is so damn full of them. Car Lists, and how to win/unlock them, etc, same for tracks. This game is so much bigger than anything that's come before, and I'm sure I'm right in saying these forums are much bigger by now as well.. I'd wager to say GTP's membership has at least doubled in the last twelve months. With that many people floating around, the more segregated the forums are, the more organized everything will be, and it'll be a lot easier for everyone.