Well, I did a bit of Googling, and I found this article published in April 2014. I cannot vouch for the accuracy but it sort of answered my own question. Maybe Roger could supply some updated info if this is inaccurate?
- Avis and Budget charge a $2.95 daily convenience fee for their e-Toll system, even on days when the renter doesn't drive on a toll road. The fees max out at $14.75 per rental per month. The driver also pays for tolls they've driven through at the "cash toll rate," not the discounted rate normally given subscribers.
- Dollar and Thrifty are moving in some states to a flat-fee, prepaid toll system called Pass24. For $5.95 a day or $27.95 a week, customers in a handful of states can prepay for both tolls and fees at one time.
- Hertz charges a $4.95 daily administrative fee for customers using its PlatePass system. Like Avis and Budget, that includes any rental days where the toll transponder wasn't used, up to a maximum of $24.75 per rental per month. Hertz also offers a Toll Day Pass; for between $9.90 and $14.30 a day, renters are covered for all tolls and fees, with the promise that "you will never receive any subsequent toll charges or administration fees."
- Alamo, Enterprise and National charge a $2.95 daily fee for their TollPass program, up to $14.75 per rental period, along with the cost of the tolls.
The following link is from Sunpass and gives details of rental car company charges for using Florida toll roads https://www.sunpass.com/rentalcar
