If I recall correctly, PD was originally going to port GT4's physics engine to the PS3, but decided that they would rebuild it from scratch to take advantage of the new hardware. If they were willing to spend such a long time on building a new physics engine, why not use brand new car models to show off the new tech? PD did this with every other GT (with the exception of GTPSP, but I think we can let that slip), so why did they reuse PS2 models? When GT moved to the PS2, there were no PS1 cars. Why? Because they would look ridiculous alongside the newer models. So why did they do it this time? Look at Forza 5, everything (AFAIK) has been redone for next-gen, the way it should have been done with GT5. carrying these outdated models into GT6 was bad enough, bring them onto the PS4 on GT7 will just be downright embarrassing for Sony.