Regarding that twitpic of the bus:
I'm assuming the bus is registered in California (it's hard for me to make out the jurisdiction on the top of the license plate; but the license plate has the letters and numbers of "CP00069." I don't know if California has a publicly accessible system to check license plate nummbers or not, butthat could lead to something, or even if it is a current tag.
In past seasons, when they have used a bus for the start (like season 1) they used two or more buses, not just one.