Yes, iData makes an adapter cable that will plug into OEM satellite antenna cable and then the SiriusXM connector on the unit. Its rather expensive, like $40, perhaps you can find it on eBay for around $20.
You can remove the plastic connector housing on the end of the OEM satellite antenna cable and it will fit into the connector for the SiriusXM unit, but its slightly oversized and won't "snap" to the connector and thus could easily fall out. I did this and wrapped electric tape around the unit several turns to hold the cable and unit connector together, it works just fine. I have purchased the iData adapter cable and will eventually get around to connecting the antenna "properly" but for now it works just fine and I can listen to SiriusXM radio with no problem, so no sense of urgency on my part.
On the Commander, and likely many Chrysler vehicles of this era, the Antenna on the roof is just for SiriusXM radio, there is a separate antenna for GPS under the dash, if you see a little plastic snap in button on the front center of the dash at the base of the windshield, the GPS antenna is under that. But its installed/removed from behind the radio.
On other vehicles, and maybe later Chrysler, now FCA, vehicles, they do have dual antennas on the roof that will have a separate connectors and cables for the SiriusXM and GPS.
