Trey Parker's inspiration for the voiceover in the Sodosopa commercials was businessman Steve Wynn. Wynn recorded voiceover for a promotional video for his Las Vegas hotel in a similar manner- very low energy whisper talking with his mouth right up on the microphone.
In subsequent episodes in the season, the CtPa Town district had the spelling changed to Shi Tpa Town.
SoDoSoPa is an abbreviation of South of Downtown South Park.