2004 Nav Question?

[Klaus]

Adding the Factory XM is not an option, as GM does not sell the digital tuner as a part.

There are a couple of adapters that allow you to connect a Pioneer XM module to the factory radio.

Also, there is a new adapter that allows AUX inputs to your factory radio. You could connect a SkyFi directly to this adapter.

Do searches on PIOGM1, AAI-GM24, and XM.