Most of us know to be on guard against hidden fees and charges when traveling, but some new car rental fees are being hidden extra well. Rental car companies are becoming famous for their extra fees, but some of the latest ones are sneaky even by their standards. While many companies now offer an E-Z Pass device for highway tolls, they will charge you for the privilege.

Avis and Budget charge $1.50 per day, while Hertz charges $2.50 per day, capped at $10 per week. But at Dollar and Thrity, it’s a staggering $8.50 per day. And that charge is for every day of the rental, regardless of how many days you use it. And it doesn’t include the tolls themselves, either. Plus, this charge is usually billed to you by a third party, so you won’t see it when you return the car. It can be pretty sneaky, so be sure to inquire about all charges before you accept them.