(clarion makes a hardwire direct connect one)
You would use a 3.5mm to RCA adapter
There are also battery powerd ones (Belkin)
Either one is used by simply tuning in to an empty (white noise) radio station.
Im assuming the XMD3-RET is not the radio you are inquiring about since you described Sirius as a feature.
Some clarion radios have an AUX input or changer port that can be converted to an ipod cable.
If you reply with a model # i can look it up for you. I am a Clarion Dealer.
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