The PS3 version of Gran Turismo could end up turning into Gran Turismo 7 for the PS4 version.
Joystiq reports that Polyphony boss Kazunori Yamauchi told a panel that by the time a PS4 version of the game comes around it could have evolved into Gran Turismo 7, although he also added that he didn’t know if the 'vision' of Gran Turismo 6 would carry over into the yet to be developed Gran Turismo 7.
GT6 will feature concept cars designed exclusively for the game by a number of high-profile manufacturing houses like Aston Martin, BMW, Honda, and Nissan. The game is out this December.
Gran Turismo will come to PS4 eventually, although in what form we just don't know.