Apparently the license plate reader doesn't ever work. I thought my plate was on my account but I went over the BB a thousand times before I got some hate mail from the toll authority with a picture of my plate and some modest monetary demands. I had forgotten to put my plate on my account. This indicates to me that their license plate reader doesn't work or barely works. I don't even have a tail-tidy or anything like that and I always go 25MPH through the plaza.
They automatically registered my bike's plate after going over San Mateo bridge. No transponder required.
Both of our shop trucks are just registered to the the account that we have and we've never had an issue. Neither one has the Fastrak physically in it.
If it doesn't work, how did they send you a letter?
I seldom carry mine. I always get charged from the license plate.