Bus operators will often find it economical to convert retired buses to use as permanent training buses for driver training, rather than taking a regular service bus out of use. Some large operators also converted retired buses into tow bus vehicles, to act as tow trucks.
Explain to an 8 year old child that is not yet 49 tall that the safety equipment built into the vehicle is for adults  not children, and a child needs to continue to use the proper equipment (booster seat) so that the adult equipment will fit, and be able to protect, their bodies in the event of a crash.
All children whose weight or height is above the forward-facing limit for their car seat should use a belt-positioning booster seat until the vehicle seat belt fits properly, typically when they have reached 4 feet 9 inches in height and are between 8 and 12 years of age.