Each bonus mission is initiated by talking to a specific character. This character is not the character the player must talk to to continue the plot. Rather, bonus missions are side stories in the game. As such, the characters that initiate bonus missions are highlighted by a smaller version of the blue dot used for main mission objectives on the radar.
Instead of the standard blue placard mission instructions are set against, bonus mission instructions are set against maroon-colored placards instead. Each bonus mission also grants the player a vehicle, unlike other missions in the plot of the game. Lastly, each bonus mission can only be completed once in a save, but can be played without succeeding more than once.
As with any mission, each bonus mission uses a track from the game library. Each bonus mission, however, shares its music with the wager race of its respective level as well. For example, the music used in This Old Shanty would be the same music heard during the wager race in Level 1.