(a) The interior of each licensed taxicab or automobile kept for hire shall be illuminated from sundown to sunrise, so a countenance may be discerned at a distance of fifteen feet at all times while such car is upon the streets within the corporate limits of the City. At no time shall the curtains or shades of such vehicle be drawn.
   (b) An automobile kept for hire shall not be enclosed by curtains unless necessitated by the weather, and at no time shall the transparent openings or windows in such curtains be covered. (1967 Code §§ 117.18, 117.19)