Well, JFM_Racer, this goes back to me saying that we are all a community. As a community, we will all have different wants and needs for the GT series. Something many of us fail to realize is that many of us love the series to begin with. We can't just have one person determine what should be in GT and what should be totally neglected. If you love a certain car or certain car company, you'd love to see it no matter what anyone else thinks of you. Perhaps the key things that can be considered are if we can all agree to something and have substantial proof that it would boost the fun factor or playability of the next Gran Turismo game, then certainly we can arrange something for the next GT. This is like voting here in America. It can be a case of something you want as Congress could likely consider a new vote or something. Well, while Polyphony Digital isn't Congress or the House of Representatives (I take Government next week, so I'm getting my terms down!), but surely they will listen or read.
Since we are a community, we'd love to think that PD looks at GTPlanet for ideas for the next game. As long as they are doable and feasible and sane, the chances are high that it will be in the game. When this forum opened up, I was an idea factory for GT5. Now, I've sobered up and just await GT5's released. On GTPlanet, I don't consider myself an insider on Gran Turismo news or anything. I consider myself more as a GT insider for public opinion and following critics. You may have remembered a thread I made called "Sound Off! How to Silence the Critics," and my other Sound Off! on how to get more arcade-type racing gamers to love GT more. As part of this community, I stay true to my own ideas about the series and where it's going, but I'm also thinking about how others may agree or disagree with me. Then having taken comments from media and game players, I start thinking about what it is that would make GT better for as many people as possible. Again, I don't work for PD. I would like to also think that with the discussions I've started and with the comments I've put forth, that we can think about what would make GT a better game for us. Because after all, who makes the game what it is- PD or us gamers? Of course, it's us. I hope some of the stuff we've discussed on here could be picked up by PD so that they can sort of learn about what will silence as much negative criticism as possible and make a game many more people can be proud of after GT4 kind of was love-it-or-hate-it to many people. As anticipated as GT4 was when it was released, not many were too fond. So I've done as much of social/public opinion stuff on GTPlanet as I could to think about what would make the next GT the best ever.
The thing that would make me most happy is if PD can look at some of the things we have discussed and hope to use it in future builds of GT games. Not just my contributions, but all of us here on GTPlanet. And if they haven't looked to GTPlanet for some help, then maybe they should start.

Because we're as much of GT fans as any other message board, and we love our Gran Turismo. So keep firing away with what you want to see in GT5. And remember, be careful what you wish for, because you just might get it.