Of the ones you mentioned, some definitely have to return.
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Motorsports Land would be a good drifting course, in addition to a nice small car course. Then again, you COULD say that MotorLand was the successor to Motorsports Land.
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Grindelwald would be a great compliment to Eiger Nordwand. Also imagine taking your favorite recent cars around scenic Grindelwald.
* Italy has three "M" tracks that I'd be happy to see in GT5 (though this is the wrong thread to do so)- Monza, Mugello, and Misano. If you can't get any or all of them, then surely bring back
Rome Circuit.
Rome-Night was simply a waste of disc space as you rarely get to race it. This was a perfectly-fine course. Why PD didn't give you more action around Rome-Night is beyond me. At least have it as "Rome Circuit A" and "Rome Circuit B" rather than just leaving Rome-Night for dead.
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Tahiti Road was fairly simple. Your French Nationals action took place in Tahiti in GT2, since Tahiti is a French territory. Tahiti looks fantastic in pictures. I wonder what a GT5 version would be like in GT5.
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Red Rock Valley Speedway was a track I slowly grown to like, especially when playing GT2 again. It's essentially two ovals linked together, yet still a competitive race track.
* Gran Turismo 2 had a lot of random roads for some of the license tests in GT2. If it's all part of one big circuit, why not make THAT into a GT course?
* Now for an all-rally section. Gran Turismo 2's version of "Smokey Mountain [North]" was much better than GT3's version, and GT2's "Smokey Mountain South" was pretty bland. Same went for the alright "Green Forest Roadway."
Tahiti Circuit should have never left. That is a FUN course. If they can bring back and improve
Pikes Peak Hill Climb, I'd be cool with that.
This would be that "you have too much time on your hands, John" part of this post.
One of the reasons you pursue real-life tracks is because they offer an experience that no game can emulate or imitate. That's even if you take a real-life course and add your own twist (like Speediapolis Ring in Enthusia) to it. I'm not saying go for more real race tracks, but I guess I'm on the standpoint of an even balance of real and fictional courses. I say PD should try to make some more original courses including completely fictional ones (like High-Speed Ring, Trial Mountain, MotorLand, Apricot Hill, etc.). Imagine PD makes a completely new original course exclusively for GT5 that harnesses what the PS3 is capable of graphically. Not many are fans of street courses, but I'm not forgetting the street courses. If Special Stage Route 11 returns, I'd be interested in two different routes based on GT1 and GT3. Maybe modify them a bit. For me, I wouldn't mind seeing the GT1 route, only making a temporary tire wall chicane rather than the 90-degree complex under the start/finish straight.
I said that you can improve on original circuits, especially those you make yourself. Do any of you ever pay attention to certain details in games if and when a sequel is developed? Think of Special Stage Route 5 in GT4. Ever noticed all the buildings under construction for that track? Imagine if those buildings were constructed fully with the next GT. Imagine if there were more trees around Deep Forest than GT4's version that left most fans disappointed. I even want to see light systems around tracks just for the prospect of racing courses in dark conditions (24 Hours of Grand Valley, anyone?). I would even like seeing Deep Forest return to the evening setting or maybe a night setting (but PLEASE provide flood lights to light things up properly!). Bring back classic tracks and improve upon them.
Random gibberish over. Have a great day!