Vaguely on topic, I have noticed that Avis cars I have rented recently in NJ have a transponder on them, so you can use the EZ Pass lanes (similar to 407 ETR transponders). They are contained in some sort of case, and if you want to use it, you pull it out so that it can be read by the EZ Pass readers.

Probably won't bother to do it here in Toronto, as they can save the money of buying a transponder and let the cameras figure out who to charge with the pictures.

Greg