XM Radio for 2005 Satellite ready radio

[Northbrook]

I am thinking of subscribing to XM radio. I just purchased a 2005 Grand Marquis GS. The radio has a SAT button but states "NO Satellite". I am trying to confirm that the radio is in fact Satellite ready. If so, I have researched that I need to get and XMD Universal Tuner Box. However, I do not know who makes the radio. I need that information to determine which Smart Digital Adapter is required.

Any help would be appreciated.