Iowa Code Title VIII. Transportation [Chs. 306-330B] § 321.374. Inspection--seal of approval

No vehicle shall be put into service as a school bus until it is given an original inspection to determine if it meets all legal and established uniform standards of construction for the protection of the health and safety of children to be transported. Vehicles which are approved shall be issued a seal of approval by the director of the department of education. All vehicles used as school buses shall be given a safety inspection at least once a year. Buses passing the inspection shall be issued an inspection seal of approval by the director of the department of education. The seal of original inspection and the annual seal of inspection shall be affixed to the lower right hand corner of the windshield.