"Custom vehicle", a motor vehicle for which the year of manufacture is after 1948, for which the model year is at least 25 years old and that has been altered from the manufacturer's original design or has a body constructed, in whole or in part, from non-original materials.
"Model year", the model year indicated on a motor vehicle's certificate of origin or, if there is no such certificate, the model year the body of such vehicle most closely resembles.
"Replica vehicle", a motor vehicle constructed or assembled by a non-manufacturer from new or used parts that, when assembled, replicates an earlier year, make and model vehicle.
"Specially-constructed vehicle", a motor vehicle reconstructed or assembled by a non-manufacturer from new or used parts, the exterior of which does not replicate or resemble any other manufactured vehicle.
"Street rod", a motor vehicle for which the year of manufacture is prior to 1949, and which has been altered from the manufacturer's original design or has a body constructed from non-original materials.
Mass. Gen. Laws ch. 90, § 2H