You can use a switchable transponder in a rental vehicle by adding the plate number to your account online for the period of time you will have the vehicle. If you do not have a switchable transponder, log into your account to order one. If the plate is not listed on your account and the transponder is not read, the transaction will be processed as a toll evasion violation, which may be subject to penalties by the 91 Express Lanes and/or the rental company.