Ala. Code § 32-18-5
The Director of Public Safety of Alabama shall approve the shape, size, color, and inscription of a sticker to be placed by any such city so operating or in which are operated motor vehicle testing stations hereunder upon the windshield of any motor vehicle so passing the tests herein provided. No such certificate shall be issued or attached to any motor vehicle until and unless such vehicle shall, upon such inspection, be found to comply with the terms and conditions and requirements imposed by law and the ordinance adopted under this chapter. The director shall also have supervision and control over the type of tests and the facilities therefor in any such motor vehicle testing station, and any such city desiring to establish any such station or to designate any privately owned station shall first procure the approval of such tests and facilities by the Director of Public Safety.
Ala. Code § 32-18-5 (1975)