I pod/xm radio connection

[inaminit]

I plan to look at a 2000 996 with the original radio/cd player soon, but have not seen it yet. My son looked at the car and noted that there is no cable socket on the front of the radio face. Is there an alternate way to cable an xm radio into the stock radio instead of plugging in to the antenna wire? Maybe a socket in the rear? Thanks in advance.