All Vibes were made by NUMMI in Fremont California. They didn't make any in Cambridge where the Matrix was built; that is a Toyota plant.
Vibes built for the Canadian market didn't have XM standard like USA market ones. I believe it was a dealer option here and not many buyers took it. If your speedo and odometer are in km, then you definitely have a Canadian car. If the cluster was changed out for one with MPH, then it still could be Canadian - and the mileage could be incorrect, too. Quite common since used cars are dirt cheap and get exported from Canada to the USA all the time. A VIN check at a GM dealer will tell you for sure.
The XM module, if you had one, lives in the trunk area, on the passenger side above the wheel well. You have to take the panel off, and there is a connector there. Your best bet if you want to stick with OEM is to find an XM module from a junkyard or ebay with the same plug and get the VIN from the car it came out of, then you can sign up with the VIN. At that time, you can also tell XM that you want to transfer that module to your own VIN.
If you really want XM, call them up, tell them you want a free radio, and they'll probably give you one, then you can connect it to the aux input jack, like this:
viewtopic.php?t=33747
Or replace the radio with aftermarket, like I did, because the knobs on the OEM radio are prone to break anyway. Then you can get all the bells and whistles the OEM radio will never have - Bluetooth, USB, HD Radio, backup camera, etc.