540 CMR, § 4.12
Owners of vehicles that are subject to the provisions of 540 CMR 4.10 and 4.11 may, on a form supplied by the Registry of Motor Vehicles, apply for a waiver from any or all of the requirements contained in 540 CMR 4.10 (2) through (6). The owner of the vehicle requesting the waiver must specify which of the requirements contained in 540 CMR 4.10(2) through (6) the owner is seeking a waiver, and a clear and concise statement of the reason for seeking a waiver. Upon submission of a certification or waiver by a contractor, the contracting Commonwealth Agency shall review the submission only for completeness of documentation and confirm that the contractor's has submitted the requested documentation to the Registrar regarding a contractor's request for a waiver. The required waiver documentation shall be submitted to the Registry of Motor Vehicles in accordance with the process established by the Registrar. Within 30 days of receipt of a complete waiver request, at the discretion of the Registrar, waivers may be granted for a vehicle that cannot comply with the requirements in 540 CMR 4.12 due to the design, operation or other safety considerations relating to the vehicle.
540 CMR, § 4.12