sentences:  To give the school bus traffic priority, red warning lights (and amber lights, for Phantom school buses sold outside of California) were fitted in the front and rear roof caps along with a side stop arm.As it served as a rear emergency exit, the Phantom School Bus was fitted with a rear window; as a requirement for rear-engine buses, the bus was fitted with a left-side emergency-exit door.A number of changes were focused on the sides of the body.