Each race in the game has a .aty file in its C/Act directory. In it, among many other variables about the race (what track path to use, what directory to search for files in, etc.), is a line that reads "NumRacers" which determines how many cars will compete in the race. The maximum amount of cars the game allows for is 20, and any number over 20 will cause the game to crash.

Underneath all of the race information, there are entries for each car, which will tell it how to perform, including its ability permissions, AI data, and other things. If you are looking to replace or add a specific character to a story mode race, you will need to add that character's codename in the entry (for example, if you're looking to add Fletcher to a race, you will need to add "Vehicle=FLE"). It should also be of note that attempting to put in more than one of the same character will crash the game.

However, for arcade mode, it is impossible to have specific characters as opponents, as the arcade mode selects computer opponents randomly from lists. These lists can be found in EventInfo.dat. Each list corresponds to a different mode - one is for road races, one is for stadium races, etc. The amount of cars the game will select depends on the vehicle number mentioned earlier in the .aty file.

For help determining what .aty file goes to which race, refer to the list below:

List of .aty files

  • RR_01 - Radiator Springs Circuit
  • RR_02 - Fillmore's Nature Preserve
  • RR_03 - North Willy's Butte
  • RR_04 - Ornament Valley Airport
  • RR_05 - Inside the Turkey
  • RR_06 - Rustbucket Grand Prix
  • RR_07 - Wheel Well Circuit
  • RR_08 - The Upper Mine
  • RR_09 - Canyon Run
  • SR_01 - Stadium Race #1
  • SR_02 - Stadium Race #2
  • SR_03 - Stadium Race #3
  • SR_04 - Stadium Race #4
  • RB_01 - Rustbucket Race #1
  • RB_02 - Rustbucket Race #2
  • RB_03 - Rustbucket Race #3
  • RB_04 - Rustbucket Race #4
  • WP_01 - Waypoint Race #1
  • WP_02 - Waypoint Race #2
  • WP_03 - Waypoint Race #3