Motor vehicle, motorcycle, or trailer salesperson means any person who, for a salary, commission, or compensation of any kind, is employed directly by only one specified licensed Nebraska motor vehicle dealer, motorcycle dealer, or trailer dealer, except when the salesperson is working for two or more dealerships with common ownership, to sell, purchase, or exchange or to negotiate for the sale, purchase, or exchange of motor vehicles, motorcycles, or trailers. A person owning any part of more than one dealership may be a salesperson for each of such dealerships. For purposes of this section, common ownership means that there is at least an eighty percent interest in each dealership by one or more persons having ownership in such dealership.