I think they need to go back to the first game and find their roots. Gran Turismo used to be energetic filled with hard music (PAL version at least) and style, it just had such an actual COOL feel about it. The later games while still good and I happily bought every one (well I was too young, had the first 3 bought for me) but they did feel a little pretentious.
Still, Gran Turismo is not my vision its someone else's so I will only be so critical.