Hex Cheat - All Cars, Tracks
To enable cheats without entering them, open your options file located in your savegame folder (c:Colin2005SG) with a hex editor. Go to location Ch - this is the 13th position from the beginnig of the file and overwrite with FF FF. Go to location 10h, this is the 16th position from the beginning of the file and overwrite with FF FF. Now you have all cars, tracks and even the secret mirror mode activated! Overwrite both hex positions with FF only if you do not want the mirror mode. Overwrite with FF FF FF to get small RC Cars!

NOTE: Always make a backup before modifying game files.