I have the AVIC-D1 installed in my rig since November... here are a few things.
Check for the new OS-5 (thats what car toys called it anyways) thats for the H3. I just had the OS-2 they rewired back in November replaced with this unit. (Car Toys called me and offered for free
)
Yes you need a new xm unit. Get the XM unit that connects to the pioneer D1 .. its part GEX-P10XMT
With that XM unit you can use the factory XM antenna. (I know because the H3 god F5fstop advised me so and there for its true) The installer swore it wouldnt fit and he was proven wrong.
I actually opted NOT to put the Pac CM1 chime module in and enjoy buzzerless bliss. You dont "need" it but if you want to retain the bells you do.
When you pick up your installed system make sure you try out ONStar while there. They will most likely need to adjust the volume (which is on the interface) Make sure the car is running and volume all the way down to listen for engine feedback.
With the monsoon system (like in my rig) has a dislike for when onstar gets activated and you'll hear a quick "pop" when the amp kicks on. Dont be suprised when it happens. And if yours doesn't let me know how it was fixed.
On a side note, and this could be in my head, I have the unit attunate(sp) instead of mute and it seems to sound better.
If you decide on a camera for the back, make sure they connect the camera to a acc 12v power supply and NOT to the reverse power (otherwise the camera only turns on when in reverse and you dont see the camera when in nav mode)
oh and if you ever think about an Ipod adaptor.. dont buy the one from pioneer. I have it and is sucks. It only displays the first 8 characters of the song your playing. Its functional but you're better off with some other aftermarket item imo.
Well I think thats all i got for now. Enjoy the nav unit. I'm just love mine!
Pictures of my nav unit