No person connected with driver training schools or private, parochial or public high schools shall engage in behind the wheel training of persons to drive or operate motor vehicles unless such person has obtained and holds a valid driver instructor permit or temporary driver instructor permit therefor issued by the Department of Motor Vehicles.

Appropriate examination for such instructor permit shall be at the discretion of the department. The annual fee for an instructor permit shall be twenty dollars, and all such instructor permits shall expire on June thirtieth. Public high school instructors shall not be required to pay a fee for a permit.