Best way to add XM?

What's the best way to add XM radio so that it's hidden? I doubt it can be integrated and controlled through the MB head unit but if anyone can tell me what they did that would be great.

Thanks

you could use one of the mini antennas and hide it in the hood fresh air cowling and use a fm modulator

In my 560SEL, The XM Radio module came with the in dash dvd screen but it's useless while I'm in Germany since there is no service out here.
 
But what is XM radio like?