§47-159.8.

§47-159.8.
   
   Any state agency, department or institution owning or operating
   automobiles or motor trucks shall have printed or painted in plain
   lettering of a size so as to be readily read the name of the agency,
   department or institution owning or operating the vehicle, followed by
   the words "State of Oklahoma." Any such vehicle need not be marked,
   however, and need bear only such license plates as are required on
   privately-owned vehicles if in the opinion of the Director of the
   State Motor Pool Division the marking of such vehicle would unduly
   hinder the agency, department or institution owning or operating the
   vehicle in carrying out its duties and functions, and if the Director
   of the State Motor Pool Division has approved in writing the operation
   of such motor vehicle without being so marked.