Confused on I Pass and Sun Pass etc--- toll roads ????

We have the I-Pass and have the Velcro strips in our other cars so we can transfer the box when needed. You need to logon to their website and register your vehicles that you are using it in. You do not need anything else for your tow. The I-system senses your vehicle and anything behind it and charges appropriately. You will not get charged unless you have your trailer/tow along. It works in many other states--just read on the signs going up to the toll or go online to the I-Pass website.