You must be at least 21 years old to rent at most SIXT stations in the U.S. Some car categories require the driver to be 25. You will also be charged an underage driving fee if you are under 25.
One-way rentals between SIXT locations are generally allowed. Check with the station before renting if you have any questions.
With this optional add-on, you have unlimited use of automated toll lanes. This saves you the cost of administrative fees and the hassle of paying cash at toll plazas.