Yes you can connect without the AUX input. It works through the radio antenna. you unplug the antenna to the radio, plug into the adapter then plug the adapter into the radio. the left over lead plugs into the sirius radio antenna out jack. select a fm radio station that is not used on your radio, then set your sirius radio to transmit on that fm station. It works much better than having the sirius radio transmit wireless to your radio.