Maryland Transportation Section 22-406
§ 22-406.
  (a)   "Safety glass" means:
    (1)   Any glass product that is so made or treated as substantially to prevent the glass from shattering and flying when struck or broken; or
    (2)   Any similar or other product that the Administration approves.
  (b)   A person may not drive on any highway in this State any motor vehicle manufactured or assembled after June 1, 1937, and registered in this State, unless the vehicle is equipped with safety glass wherever glass is used in the motor vehicle in doors, windows, windshields, and wings.
  (c)   A person may not sell any motor vehicle manufactured or assembled after June 1, 1937, registered or intended to be registered in this State and driven or intended to be driven on any highway in this State, unless the vehicle is equipped with safety glass wherever glass is used in the motor vehicle in doors, windows, windshields, and wings. Each sale in violation of this provision is a separate offense.
  (d)   The owner of any motor vehicle may not have broken glass in the windshield of the vehicle replaced with any glass other than safety glass.
  (e)   The owner of any motor vehicle may not have safety glass, broken or otherwise, in doors, windows, or wings of the motor vehicle replaced with any glass other than safety glass.
  (f)   A person may not install in the doors, windows, windshields, and wings of any motor vehicle any glass other than glass required by subsections (d) and (e) of this section.
  (g)   (1)   The Administration shall compile, maintain, and publish a list, by name, of the types of glass approved by it as conforming to the specifications and requirements of safety glass as set forth in this section.
    (2)   The Administration may not register any motor vehicle that is subject to the provisions of this section unless it is equipped with an approved type of safety glass and shall suspend the registration of any motor vehicle subject to this section that the Administration finds is not so equipped until the vehicle is made to conform to the requirements of this section.
  (h)   In case of any violation of any provision of this section by any common carrier or person operating under a permit issued by the Public Service Commission of Maryland, the permit shall either be revoked or, in the discretion of the Commission, suspended until the provision is complied with to the satisfaction of the Commission.
  (i)   (1)   Except as provided in paragraph (4) of this subsection, a person may not operate a vehicle registered under § 13-912, § 13-913, § 13-917, or § 13-937 of this article on a highway in this State if:
      (i)   In the case of a vehicle registered under § 13-912 of this article, there is affixed to any window of the vehicle any tinting materials added to the window after manufacture of the vehicle that do not allow a light transmittance through the window of at least 35%; and
      (ii)   In the case of a vehicle registered under § 13-913, § 13-917 or § 13-937 of this article, there is affixed to any window to the immediate right or left of the driver any window tinting materials added after manufacture of the vehicle that do not allow a light transmittance through the window of at least 35%.
    (2)   If a police officer observes that a vehicle is being operated in violation of paragraph (1) of this subsection, the officer may stop the driver of the vehicle and, in addition to a citation charging the driver with the offense, issue to the driver a safety equipment repair order in accordance with the provisions of § 23-105 of this article.
    (3)   A person may not install on a window of a vehicle any window tinting material that does not comply with the light transmittance requirements specified in paragraph (1) of this subsection.
    (4)   (i)   A person who must be protected from the sun for medical reasons is exempt from the provisions of paragraph (1) of this subsection if the owner has, in the vehicle at the time the vehicle is stopped by a police officer, a written certification that details the owner's medical need for tinted windows, from a physician licensed to practice medicine in the State.
      (ii)   This subsection does not apply to tinting materials that:
        1.   Are affixed in such a manner so as to be easily removed; and
        2.   Are being used to protect a child less than 10 years of age from the sun.
      (iii)   Nothing in this subsection may be construed to:
        1.   Allow any tinting materials to be added to the windshield of a vehicle below the AS1 line or below 5 inches from the top of the windshield; or
        2.   Alter or restrict the authority of the administrator to adopt regulations regarding vehicle windows, except with respect to the light transmittance requirements specified in this section.