Which of the following pieces of information is not required to be kept in a dealer's records?

In the context of a dealer's record-keeping requirements, customer complaints are not mandated to be documented in the same manner as other vital information. While tracking customer complaints can be beneficial for service improvement and customer relations, it is not a statutory requirement under the regulations governing dealerships.

On the other hand, employee names, vehicle sale certificates, and proof of payments are critical elements that dealerships must retain to comply with legal obligations, maintain transparency, and ensure that they can effectively manage business operations. Employee information is necessary for payroll and compliance with labor laws. Vehicle sale certificates are essential for documenting ownership and transfer of vehicles, while proof of payments serves to validate transactions and protect both the dealer and the customer from disputes. Hence, while customer complaints are important for operational improvements and customer service practices, they do not fall within the required record-keeping framework established for dealers.