I am looking at putting an AVIC-Z1 in this truck and have read through a lot of the forums here and have figured out how to make the OnStar work and the steering wheel controls. What I am curious about is, will the factory XM tuner work with the Z1 or do I need to buy another tuner? Also, will I still be able to use the factory rear dvd system with the new head unit? Thanks in advance.

No to both. the factory xm and dvd system can't be hookedup to the z1. though you can reuse the factory xm antenna so you don't have it sitting there doing nothing.

Really? I asked my installer and he said no. Does it just plug right in?

No it doesn't exactly plug right in. YOu can modify the plug a little to get it work properly.

any idea how i can make the factory xm antenna work with a sirius add in box? 8) hijacked thread! hehe

sirius and xm both use the same style plug just a different caseing around it, if you pull the white clip off the yellow plug case then pull the case off it will plug into eather one.

I have used the factory GM XM antennas on both aftermarket XM and Sirius tuners. You have to remove the plastic housing around the antenna end. I think use a small zip tie on the antenna end once its connected to the tuner just to ensure it does not slip off.