The term "automobile utility trailer" when used in §§ 56-3-400 to 56-3-420 shall mean and include any trailers suitable for towing by a private passenger automobile, the use of which is confined to the private hauling of personal property for intrastate or interstate use, or combined intrastate and interstate use. The term "automobile utility trailer" shall not include trailers or semitrailers rented or leased to any person for use by such lessee in the furtherance of or as an incident to any commercial or industrial enterprise in interstate commerce or for the use in connection with any business or occupation carried on in interstate commerce by the lessee.