K.S.A. 8-603

It shall be unlawful for any manufacturer to sell or enter into a contract to sell any motor vehicle or vehicles or other specific commodities to any dealer on the condition or under an agreement, either express or implied, that such dealer shall finance the purchase or sale of any such motor vehicle or vehicles or other specific commodities only with or through a designated person, and any such condition, agreement or understanding hereby is declared to be void and against the public policy of this state.