It works only with 996 turbo 00, Boxter 97, or the 911 Carrera RS. All you have to do is open the folder (need for speed.../game data/car data/) and change the file names of the cars. There are two types of cars each 996, 996 f, boxter, boxter f, and carrera rs. Now you have to rename them the ordinary 996 file to 996f and 996f to 996 and so on.