Which of the following is NOT typically an additional driver requirement?

The reasoning for why having their own personal auto insurance is not typically an additional driver requirement lies in the policies of most rental car companies. When an individual rents a vehicle, the rental agreement usually includes some form of insurance coverage provided by the rental agency itself. While having personal auto insurance can be beneficial and may cover rental vehicles, it is not a prerequisite for being added as an additional driver.

The other requirements—being at least 25 years old, presenting a valid driver’s license, and being an authorized user on the rental agreement—are standard practices among rental car companies to ensure that additional drivers are legally qualified and capable of safely operating the vehicle. Age restrictions help mitigate risk, a valid driver’s license confirms the driver's ability to operate a vehicle legally, and being an authorized user protects the rental company from liability issues. Therefore, personal auto insurance stands apart as something that is not generally mandated for an additional driver.