What you thought of: Renting the car far in advance.
What you forgot to save for: The toll pass charge.
How to get a good deal: If you're going to be doing highway driving, getting an electronic toll pass such as E-ZPass, I-PASS or FasTrak from your rental car agency might seem too convenient to be a good deal. It is. "If customers decide that they would like to use the electronic tolls and our devices, there is a fee, and it is a fee of $2.95 per day of the rental, up to a maximum of $14.75 per rental month. That doesn't include the tolls—the customers are still responsible for the incurred tolls," says Paula Rivera, manager of public affairs for Hertz. Additionally, as soon as you use the pass once, you're charged for it every subsequent day of your rental, even if you don't use it again for the rest of the trip. If you're traveling in your home state or a state that uses the same pass as yours, you'll save money by bringing the one you use at home. Out of state, it's best to do things the old-fashioned way and use the cash lanes.