I have an 08 A4. I went to the dealership yesterday to inquire about installing/activating satellite radio. I bought some kit from best buy and that's all I needed I though. I looked in the trunk and the compartment to the left was empty. I wasn't sure if that was the right area to look. I found the same model and year on the floor and looked in the trunk...sure enough there was the tuner. The previous owner took the tuner out before I bought mine. I found one for 100 bucks used from a crashed Audi. Install seems pretty easy too. Then what do I need to have the think installed and working?