Help! Sirus XM Radio Function

[CY1957-XLR]

Does anyone in our forum have an XLR (with factory radio) that has the XM Radio functioning?
I recently tried to have Sirus "start a subscription" for my XLR radio, since it appears to have XM functionality.
Shows Radio ID on channel 0, has XM1/XM2 presets, and shows station names.
After many "refresh signals" and troubleshooting with Sirus, still radio shows "No XM Signal".
Sirus said maybe would have to be "updated/reset" at the Cadillac Dealer, which I do not plan on spending $$ on for that.
Is it possible that the XLR's were "prepped" with that radio, but only had it working if an "antenna" was added?
I recently saw a few XLR's for sale, and on trunk was a "bulge/sharkfin", which I would think is some kind of antenna?
My XLR has no visible antenna like that or other, so not sure if it is hidden or not?
Any feedback would be helpful, as would be nice to know if the older radios will even work with XM Radio anymore.

 

[justdennis]

I have a 2007 V with XM and it works great and no antenna on the trunk.

 

[CY1957-XLR]

Dennis, did you have any issues activating it?
Did you have to disconnect battery at all to "reset it".
That was the suggestion from Sirus today.
Thanks

 

[justdennis]

No problems at all, it has worked from day one.