I am the owner of a 2005 Avalanche with NAV and XM. I added a Neucleus IPOD adapter, GM Class II . I have replaced it twice and now have a Scosche version, same manufacturer, and same problems. The XM data is now deleted on two lines. to get it back I need to disconnect the NAV system completely. I have been in touch with the engineer who developed the system. I offered to put this out for a survey of problems, as the software engineers are interested in coming up with fixes. Any experiences you are having would be helpful. I have initially thought there may be a NAV problem as American INternational, the distributor, says they do not have any reported problems with the device. That being said, my NAV has been replaced twice without any effect. It appears that the device blocks the data from XM. The device is sold under the following names: Scosche, Peripheral, Neucleus and Crux. I look forward to your comments.