I want as many cars as the next guy but it's not that simple, there is so much more going on with the environment, the physics etc. I use DriveClub as an example. A gorgeous game, heights of realism never before achieved in a console game, or any racing game for that matter...but...they couldn't do it at 60fps. In order to fit all that whizbang visual stuff in, they had to cut back something. The PS4/XBone are mid-range at best pcs, far more powerful than a PS3, but far behind what is even a typical gaming pc these days.
I can say with near certainty that if you expect 64 cars on any track on any console, you're going to be disappointed.