Where is everyone mounting this box. Under the dash if you can find a place I would assume. As far as the attenna can it be monted unobstructed under the dash like the GPS antenna or does it need to on the exterior? I have a 2001 ML 320 so if anyone has any experiance mounting this head unit in this vehical I'll be doing mine this weekend so any help tips or pointers would be greatly appreciated.

As far as I know, the satellite radio antennas MUST be mounted in clear view of the sky. Not sure if it can be mounted inside, like on the dashboard or something, but I'm 95% sure it can't but under the dash.

I have mine posted on the rear console behind the seats so it goes out the back window and it works perfectly

I installed my D2 with the Sirius hardware yesterday and thankfully there was some space behind my console to tuck the Sirius unit in (thankfully the Sirius unit is pretty small as I didn't want to have to run wires to the rear of my car). I have both my GPS and Sirius antennas mounted on my dash with the wires hidden and I've had no problems with receiving signals on either one.