What is KLM? I manage a National and I'm not familiar with that.
Generally additional drivers are extra unless it's a spouse or adult over 25 on your insurance policy or if you're in Emerald Club.
Insurance will always be an optional add-on unless you have a corporate account with the LDW included.
To my knowledge, all National Car Rentals come with unlimited miles. The only exception is if you are again using a corporate account that has a mileage limitation.
The National I worked for went with the rules posted on the website: Any additional driver (including a spouse or domestic partner) will pay a daily fee of approximately $10 per day unless the primary renter is a member of Emerald Club or has a Corporate Contract Agreement.
Emerald Club Members in the United States and Canada are allowed to have the following Additional drivers without a fee:
Emerald Club member's spouse, common law spouse, or domestic partner who has the same address on the driver's license as the Emerald Club member and meet normal renter requirements.
Immediate family member, Mother/Father, Son/Daughter, or Brother/Sister who has the same address on the driver's license as the Emerald Club member and meets normal renter requirements.
Corporate Contracts / Business Benefits Member in the United States and Canada are allowed the following additional drivers at no charge:
Commercial (corporate) rentals, the renter's business partner, employer or fellow associate, who has an assigned corporate contract with National and drives the car for business purposes and meet normal renter requirements.
All other additional authorized driver situations are subject to a daily charge.
Exception states that allow the spouse to be an "Automatic" Authorized Driver under all circumstances are; California, Illinois, Missouri, Nevada, Oregon, and Wisconsin. There is no additional fee for the spouse to drive the vehicle in these states.