Juniper

In Mario Kart Wii, many characters are already unlocked in the beginning of the game and do not need to be unlocked via completing any requirements.

However, modifying the game to cause them to be unlocked reveals an interesting detail: every character, including the default ones, has a line of code assigning a voice file to play when they are unlocked. The voice files all come from the different samples the characters use on the selection screen, but they seem to be hand-picked (e.g. not always using the first file in the list as would be the case if this code was automatically generated as a failsafe).

As such, this raises the possibility of many more of the characters being unlockable at some point during development.