Sonic and Tails appear in the game's TV commercial, but none of the characters in the Sonic franchise appear in the game and neither are there any references to them at any time in the game.
In the manual, Gus's taxicab is described as a "old, junked out 1955 jalopy". In the game, it is shown to be in good condition, consistent in appearance with other cabbies' taxis.
The Caucasian female customer wearing a red business outfit has the voice of an African-American woman. In the sequel Crazy Taxi 2, she is given the proper voice of said race.