Any threat, expressed or implied, made directly or indirectly, to any person engaged in the business of selling motor vehicles at retail in this state by any person, or any agent of any 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 such person so engaged in the manufacture or distribution shall terminate his 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 or number of motor vehicles only or through a designated person or class of persons or sells and assigns the conditional sales contracts, chattel mortgages or leases arising from his retail sale of [motor vehicles or any one or any number thereof only to such per]son 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 such person so engaged in such manufacture or distribution of motor vehicles, and shall be prima facie evidence of the fact that such person so engaged in the manufacture or distribution of motor vehicles has sold or intends to sell the same on the condition or with the agreement or understanding prohibited in Section 1 [57-11-1 N.M. Stat. Ann.] of this act.