I just did a sirius install for the b7 with the factory tuner. The forum I saw on how to do it said to rip out the back interior, take out the wheel, etc. This was completely unnecessary. All I needed to do was open the storage area in the trunk of the car. I located the area where the sirius box goes and took a screwdriver and popped the box open. Once the box is opened, you can slide it out and you will have access to the area otherwise only accessible by tearing out the lining. I figured there was an easy way to do this because I doubt that when they do it via audi they tear out all of the interior lining to do the install.