Municipalities may provide vehicles for the use of the mayor, any member of the local governing body, any board or committee member elected or appointed by the mayor or local governing body, and any official or employee whose salary is set by charter or general law. Such vehicles shall be provided pursuant to a written policy adopted by the municipal legislative body. The written policy for vehicle use shall be separate from the travel and expense policy provided for in the previous sections of this part and shall contain no other subject matter.