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 engaged, either directly or indirectly, in the manufacture or distribution of motor vehicles, that such person will discontinue or cease to sell, or refuse to enter into a contract to sell, or will terminate a contract to sell motor vehicles, whether patented or unpatented, to such person who is so engaged in the business of selling motor vehicles at retail, unless such person finances the purchase or sale of any one 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 retail sales of motor vehicles or any one or number thereof only to a designated motor vehicles or any one or any number thereof [sic] only to such person or class of persons 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 condition or with the agreement or understanding prohibited in Section 1 [57-11-1 N.M. Stat. Ann.] of this act.