The standard included cars should all be in the first PS4 iteration
It took a while for Gran Turismo to hit the PS3, first as a Prologue release. So much so that Gran Turismo 6 didn't even hit until the after the PS4 released. Polyphony seems to want to change that, though it told Eurogamer that Gran Turismo 7 will miss the overly optimistic 2014 release it had mentioned.
"We are working on the title," series creator Kazunori Yamauchi said. "I don't think it'll make this year!" It will come as a full game, though. "I don't think it'll be a Prologue," Yamauchi said.
The first PS4 entry should bring with it series standard cars. "I think the quality of the sounds in Gran Turismo 6 will be improved," Yamauchi also said, "but most of the work will be done in Gran Turismo 7."