That's sort of what got me thinking MX5, if the engine is going to have the "flexible expandability" I'm hoping it is then it might even be like a "prologue" version of the PS4 engine so things they do with it on a relatively simple level for the PS3 can be converted easily to the PS4 and jacked up to 11.
I don't mean so much that they might have gone out and scanned all 800+ standard cars to premium, rather that for the new engine they might have produced a better quality of "standard car" because they had to make new 3D meshes with better quality textures instread of simply importing the crappy ones from GT4. Then come time for the PS4 version those better quality standard cars would be much more easily jacked up to 11 with new PS4 technology for carpet pile, carbonfiber weave, metallic flake paint and even shaped better by plugging in manufacturer specs / dimensions for size and shape.
If I were to make a real world analogy it might be like trim levels of cars:
Old Standard Cars = base model
New Standard Cars = sport package
Premium Cars = special edition / in-house tuned version
But I could just be talking the world's most impressive bullshit and we'll probably end up with the same crappy standard cars we've already got
.