The department shall issue special plates as applied for, which shall display the general distinguishing number assigned to the applicant. Each plate so issued shall also contain a number or symbol identifying the plate and distinguishing it from every other plate bearing the same general distinguishing number. The fee for each special plate is forty dollars for a two-year period or part thereof. The fee for a special plate used on a vehicle that is hauling a load or towing a trailer is seven hundred fifty dollars for a two-year period or part thereof. [SS15, §1571-m14; C24, 27, 31, 35, §4892; C39, § 5004.04; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §321.60 ] 84 Acts, ch 1305, §57 ; 92 Acts, ch 1175, §3 ; 2006 Acts, ch 1068, §43, 57 ; 2014 Acts, ch 1123, §28 Referred to in §321.42 , 321.57 , 321.115