<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by My Wife's Hummer:
i don't know about the xm/sirius together, but that would be cool. as far as the tuner, the factory one is up above the glove box, but you can only see it with the radio out and looking back into the dash over top of the glove box. box is fairly small. the dealer might have installed the pioneer tuner back in the dash behind/next to the head unit. that is where i am planning on setting mine. hope this helps. </div></BLOCKQUOTE>
Thanks for the response; it helps. Siriusly,

you can have both. There are icons for both and since Pioneer uses IP-bus, the Sirius tuner can be plugged into the back of the XM tuner. The installation house wants $180 for installation only, but I want to do it myself.
I removed the glove box and peered to the left and saw the headunit but couldn't find the XM tuner anywhere near it.
Do you know how to get to the back of the dash without having to remove the Pioneer headunit? Would it be possible to remove the whole dashboard panel?