The Bus is commonly found within the city of Los Santos, but it also spawns in Paleto Bay. Very slow, barely able to climb hills. The Bus has a civilian radio.

If a Police Cruiser is chasing an NPC-controlled Bus and manages to stop it, the driver as well as all of the passengers will disembark and get into a gunfight with the police. After watching this occur a few times, it's obvious that only the front doors of the bus are functional. NPCs never make use of the rear doors.

??????????????????? Into The Ocean

You need to find a blue Bus. Once you have found one climb on top.

Slam your foot down on the bus once. (Kick Attack: "A" Button on Xbox, "X" Button on PS3.) Watch out for police, as this counts as Assault. The Bus should start speeding through traffic. The Bus will then proceed to drive out past the desert and into the country. From there it will go down a road, turn around, and drive into the ocean.