thats a real shame i realy wanted the ferrari enzo to race an f1edit how is that a huge change its one option its a huge loss and you should realy do it!

or there is always need for speed shift
First:
I will try to explain it to you in a simple way.
It's all about memory and the way you produce your game engine around it. Doing a option like that would mean re-write the game's engine to fit the new memory use. That type of option means resources and money.
Second:
Between Shift and ProStreet I chose ProStreet and for a game that represents Ferrari, Ferrari Challenge is the best. It's up there with Sega's F355. The best console racing games ever made. To the point that you spot driving characteristics of some Ferrari cars thought I noted that Eutechnyx did softed those to make the cars more playable. This you will not find in another game driving the same Ferrari on a PC or Console.