Yes, I think you're right, and unfortunately that's what we did. The trip was one that was planned very last minute, and as a brand new renter, I only had so much time to scramble and try to figure out a ton of different rental variables. Your site was extremely helpful, but unfortunately I did have to do a lot of figuring for some unique things I encountered, and somehow I forgot about toll planning. I'll know better going forward.

I'm somewhat hopeful that because my girlfriend opened-then-closed the transponder perhaps that triggered something that activated it, as that seems like the far less pricey route. I guess I'm just assuming though that the little box it's in deactivates it and/or blocks all signals, so my presumption is that unless it somehow has a history of the box being opened that Hertz electronically accesses and considers to be an addition to my rental, then it would likely be a plate-associated matter. Still, I think I'll give Hertz a call and see if it's too late to tack on the box, and then have any charges I incurred directed through the transponder. Guess we'll see what happens.

By the way, I did use your website to find and book the best price, so thank you. It's possible that I missed something, but I do have a few suggestions to help others who inexperienced avoid a few pitfalls.

1. I've seen some posts indicating that rental companies did not honor a booking b/c the individual did not "confirm" the booking, and they are then left rebooking at the counter at a much higher rate. To someone who's new to this, the need to confirm after reserving isn't really very apparent, and the only reason I did so was because (1) it didn't show up on my Hertz account, and (2) I was lucky to read that horror-story post I mentioned. A big red reminder to confirm would be a very helpful thing if you can put it somewhere for people using your service.

2. I do have status with Hertz, and part of the reason I figured out that I need to "confirm" was because I couldn't see the booking in my profile, and was concerned that my status wouldn't be applied to the booking. It seems that I was correct, and would've been left waiting in line and then finding out the booking and my status were not attached. Since your site directed me to Priceline, that was why it didn't populate naturally into my profile, I guess. This sorta goes with #1, but a notice to users that third-party bookings won't associate with their status unless they confirm is probably a good idea too (though this obviously falls into the category of #1.)

3. Because I booked with Priceline, I couldn't confirm with my Priceline code using the Hertz website. When I called, they were able to pull it up, confirm it and attach it to my profile without any issue. The recording prior to talking to a rep indicated that a 5% phone confirmation charge would apply, but the rep indicated that wasn't the case, and was only for phone bookings -- my bill reflects no additional 5% fee, so it seems this was correct. I suspect that the inability to confirm a booking online, and the need to call is something that will be encountered by many who book through a third party site, so perhaps a heads up from AutoSlash that this may be very helpful.

Anyway, I want to thank you again for the great resource (and it's pretty cool to see you on this forum too.) Thanks again.