I used the the XM radio modulator antenna adapter. It's mounted between the the OEM radio antenna and the XM antenna and tune it to the lowest clean channel.
In addition I mounted the XM (Roady) inside the glove box leaving conduit long enough to be removed by driver to tune another station if needed. We primarily listen to 2 stations.
It sounds great, out of sight and with the exception of the XM antenna, laying neat on right side dash, you would not know it's there.
PS. You will need an a european antenna adapters as in addition. Crutchfileds supplied all my junk here, ask them and they will forward the all the requirements. If you use the Scorce it will adapt to any other head phone jack input.

Good Luck