No person who is engaged in, or about to engage in, the business of selling motor vehicles at retail shall enter into any contract, agreement, or understanding, express or implied, with any manufacturer or distributor of motor vehicles that the person will sell only to a designated person, or class of persons, all or any part of the credit sale contracts arising out of the sale by the person of motor vehicles, or that the person will refuse to sell such credit sale contracts to any designated person, or class of persons. Any such contract, agreement, or understanding is declared to be against the public policy of this State and to be unlawful and void.
HRS § 437-32
Credit sales, generally, see chapter 476.