Im looking into getting XM and sirius connected to the same head unit.     I have an Alpine CDA-9827 head unit which is "versatile link" ready.    Now the  "alpine KCA-410c"  is an "ai-net multi changer/verstatile link adapter" (https://www.crutchfield.com/S-GeBTvBYARAO/cgi-bin/ProdView.asp?g=57900&id=essential_info&i=500KCA410C).   

now I guess I really have 2 questions.....first of all the versatile link thing says it only works on head units from 2001 and up.....I bought my head unit after 2001....but Im not positive it was actually made b4 2001...any way to check?

2nd.....could I hook up a XM receiver and a Sirius receiver to the versatile link.....as opposed to 2 changers?

I hope this all makes sense

one more quick qestion....my head unit is "MM Driver (Hard Disc Drive) Ready"     any clue what this means?

just do more research then you already have, the answers are all in front of you, especially on the Web. in any event, the answer to all your questions are Yes!

the KCA-410C will work with your HU, the cda-9827, and it is designed to be used with 2 changers and 2 aux inputs, in this case, it seems what you are most interested in are the aux inputs.

you can hook up both an XM and a Sirius Sat revceiver to the KCA versitile link adaptor, enabling you to listen to both satellite services.

what receivers will you be using to perform this task? two plug-and-play receivers i am guessing, they would be the most desirable.

post here what you would like to do with the whole thing, i'm very interested to hear about the envisioned finished product.