(a) An electrical contractor, electrical sign contractor, and residential appliance installation contractor shall display the contractor's business name and the number of the license issued by the executive director on each vehicle owned by the contractor.
(b) The information required to be displayed must be:
(1) printed in letters and numbers that are at least two inches high and in a color that contrasts with the color of the background surface; and
(2) permanently affixed in conspicuous places on both sides of the vehicle.