So Kaz has said this game is in development (shock horror).
And
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Sigh, standard models.
"We are working on the title," said Yamauchi. "I don't think it'll make this year!"
And
And when Gran Turismo 7 does come around, the standard car models that persist from 2004's Gran Turismo 4 will most likely feature.
"I doubt that we'll be throwing away the standard cars," said Yamauchi. "Each car has its own fans. So I think we'll hang on to the archive. In the meanwhile, some of those cars we may be able to make into Premium cars as they become available - but basically we're more focussed on increasing the number of premium cars."
source
Sigh, standard models.