Any threat, expressed or implied, made to any person engaged in the business of selling motor vehicles at retail in this state by any person, or any agent of any such person, who is engaged in the business of financing the purchase or sale of motor vehicles or of buying conditional sales contracts, chattel mortgages, or leases on motor vehicles in this state and is affiliated with or controlled by any person engaged, directly or indirectly, in the manufacture or distribution of motor vehicles, that the person so engaged in such manufacture or distribution shall terminate his or her contract with or cease to sell motor vehicles to such person engaged in the sale of motor vehicles at retail in this state unless such person finances the purchase or sale of any one (1) or number of motor vehicles only with or through a designated person or class of persons or sells and assigns the conditional sales contracts, chattel mortgages, or leases arising from his or her retail sale of motor vehicles or any one (1) or any number thereof only to such person so engaged in financing the purchase or sale of motor vehicles or in buying conditional sales contracts, chattel mortgages, or leases on motor vehicles shall be presumed to be made at the direction of and with the authority of the person so engaged in the manufacture or distribution of motor vehicles, and shall be prima facie evidence of the fact that the person so engaged in the manufacture or distribution of motor vehicles has sold or intends to sell them on the condition or with the agreement or understanding prohibited in § 4-75-408.