It shall be unlawful for any person who is engaged, either directly or indirectly, in the manufacture or wholesale distribution of motor vehicles to sell, or enter into a contract to sell, motor vehicles to any person who is engaged or intends to engage in the business of selling such motor vehicles at retail in this state, on the condition or with an agreement or understanding, either express or implied, that the person so engaged in selling motor vehicles at retail shall in any manner finance 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 shall sell and assign the conditional sales contract, chattel mortgages, or leases arising from the sale of motor vehicles, or any one (1) or number thereof only to a designated person or class of persons, when the effect of the condition, agreement, or understanding so entered into may be to lessen or eliminate competition, or create or tend to create a monopoly in the person or class of persons who are designated, by virtue of the condition, agreement, or understanding to finance the purchase or sale of motor vehicles or to purchase such conditional sales contracts, chattel mortgages, or leases. Any such condition, agreement, or understanding is void and against the public policy of this state.