Supreme Judicial Court, February 7, 2014

An individual’s use of a license plate cover (tinted or not) does not violate G.L. c. 90, §6 or
540 Code Mass. Regs. § 2.23(1) unless it obscures the registration numbers.

G.L. c. 90, §6:
“…The said number plates shall be kept clean with the numbers legible and shall not be obscured in any manner by the installation of any device obscuring said numbers…”

540 CMR 2.23(1):
“… [n]o reflectorized number plate issued by the Registrar of Motor Vehicles and mounted on any motor vehicle or trailer shall be covered with any glass, plastic or similar material if such material reduces the legibility or substantially diminishes the reflective qualities of such plate.”