Yes. Log in to your FasTrak or ExpressAccount here and add your rental car's license plate to your account. Enter the date you will return the car in the End Date field. Then, place the FasTrak transponder on the rental car's windshield. Simply moving the transponder into the rental car does not guarantee that tolls will be charged to your account. The best way to do this and avoid potential fees and penalties is to temporarily add the rental car license plate to your account.