I've had the blitzsafe in my 05 r53s for a few years (that's the one that connects into the input in the right rear panel of the boot and has the cable you run up to the front of the cabin to connect your ipod/iphone). For Christmas I received XM Onyx vehicle kit. Could use some help and/or advice:

1. If I'm going to install the XM device then I have to disconnect the blitzsafe, right?
2. Or, do I have to buy the y-connector type device to feed in two different aux devices?
3. If you run more than one aux using the oem HU, how do you get the radio to select which one you are using (or is it if both are connected and playing, both will feed a signal through the HU)?
4. Lastly, I have the Sirius app on my iphone (and at least at present) the subscription that came with my Onyx includes the internet radio service - should I just send the Onyx back and just do an internet based subscription? I mean, is there any reason to have the Onyx installed in my car if I can get the signal and stations from the Sirius iphone app?

Appreciate the help