At its discretion, the legislative body of any city may, by ordinance, provide for the appointment, removal, qualifications, terms of office and numbers of members of parking place commissioners for such city. Such board shall have all of the powers and duties of parking place commissioners appointed under this part. Such board, so appointed, may be an existing board created by city charter or ordinance or a new board created by ordinance. Such board may act for all vehicle parking districts established within said city under this part.