Except as otherwise permitted by law, it shall be unlawful for
any person to attach to or display upon any automobile within the
City of Buffalo the large metal emblem of the Department of Police
of the City of Buffalo known as the "police shield" or any other insignia
or letters indicating that said automobile is a Police Department
vehicle, except that the police shield, insignia or lettering may
be attached to and displayed upon City-owned automobiles used by any
member of the Department of Police.