Advice 3.

Put all additional drivers in the car rental contract. Whenever you let someone not included in the car rental contract drive the vehicle, you risk voiding the contract. Claims against the company's insurance coverage — and even your own personal insurance coverage — may be compromised." So swallow the added fees and put everyone in the contract. Most companies won't charge extra for your spouse, but you should ensure that his or her driving privileges are provided for in the contract.