Getting on the subject a little late...but, we have had EZpass for a number of years. We got ours from Massachusetts; they were free at the time. We have two transponders. One stays in the motorhome and has a profile that indicates that we tow a car four wheels down. The second transponder stays in the glove compartment wrapped in two layers of aluminum foil to block signals until such time as we are in the car touring an area with tolls. This method has worked well for us. We especially like the high speed EZpass lanes that allow you to breeze through at 50+ miles an hour.