WAC 392-143-050
WAC 392-143-050. Resold school buses
A school district which sells a school bus to anyone other than another school district must be responsible for removing the school district's name and number and all lettering and markings identifying the vehicle as a school bus prior to its delivery to the purchaser. However, if the district sells the school bus to a private party who certifies in writing that the school bus will be used as a private carrier bus, the district need not remove the four or eight light warning system and stop signal arm.