It shall be unlawful for any person, firm or corporation to park any vehicle or trailer in excess of 20 feet in length and in excess of 6 feet 6 inches in height on any street, alley, parking lot, or other public place, or within the front yard area in any residentially-zoned area between the hours of 2:00 a.m. and 6:00 a.m. when said area has been established as a no parking area pursuant to Sect