How about a Developer's Kit? You could buy the program for $50.00 or something. Then you could make entirely new cars. Say you wanted a Ferrari Enzo. You could make the mesh of one in the mesh section of the program, then move onto the engine, giving Horsepower, what mods you can do, and how they affect the car. Then you would move onto the drivetrain and put in the custom rims and such, and how the tires and mods change the handling, then finally go to the textures and engine sounds part and put in the paint gloss and available colors.
I can think of at least three problems, though.
(1)- It would be very time consuming.
(2)- I'm not sure of it's legality (with copyright issues).
(3)- I'm not sure where the heck the files would be stored (PS2 HDD?).