Cesar Vialpando is Kendal's boyfriend and ledar of the hispanic street gang, Varrios Los Aztecas. At first, CJ does have some difficulties with him, but he becomes CJ's best friend. He introduces himself to CJ after CJ wins a lowrider contest, helps CJ and the Grove Street Families get back to the top, and remains a loyal friend to CJ for the duration of the game. He is also an excellent lowrider driver.
Like CJ, Cesar was forced to leave Los Santos with Kendal after the intinal Ballas Ambush on the Grove Street Families, and his gang's influence in the city diminished sharply. While in exile, he gets CJ into some grief by introducing him to his cousin, Catalina. After arriving in San Fierro, he and CJ work together to get revenge on the people who double crossed them. Together, they were able to kill T-Bone Mendez. Later, Cesar puts his Driving skills to good use by ading CJ in obtaning several sports cars their newly estblished Car business. During one of the last missions of the game- "Los Desperatos", Cesar tells CJ he Wants to propose to Kendal. He wants CJ talk to Sweet about this because Sweet expresses his Disaproval of cesar in the early stages of the game.
Cesar was voiced by Clifton Collins Jr., who broke into mainstream in 1997 as gang thug Cesar In the film 187.