One problem related to rearview mirror has been reported for the 2005 GMC Envoy. The most recently reported issues are listed below.
The only problem is with the memory seats and mirrors. On prior year Envoys, when you pressed the unlock button on the remote, the seats and mirrors would recall to that drivers position. Now you have to push the 1 or 2 button on the door, while in park, to recall the seat and mirror positions. There is no tie with the remote and the memory seats. I don't know why gm would do away with this feature, but it is very inconvenient and in my opinion - a big step backwards.