Ancient Wu was based on Lo Pan from Big Trouble in Little China (1986). Both characters were played by James Hong.
Snoop Dogg is an unlockable character.
George's badge number is 714, the same as Det. Joe Friday in the many manifestations of "Dragnet".
There are numerous references to Grand Theft Auto hidden throughout the city (for example, a billboard featuring a take off on the GTA pink bikini picture).
Throughout the city, there are billboards advertising a True Crime movie coming out in the fall of 2005. What's actually coming out at that time is True Crime: New York City (2005).