The following instructions are based on my personal experience and are in no way an official set of instructions. I provide no warranty whatsoever. If you use these instructions to install your own Audi satellite tuner, you do so at your own risk. I doubt Audi will cover any issues under warranty without charging you for the entire install. So, good luck.

These instructions are only tested for 2006 Audi A3 8P Concert II and Symphony II (BOSE) non-NAV

This process should work with either of the following SAT Tuners:

8E0 057 593A - XM
8E0 057 593 - Sirius

These tuners can be purchased at your local Audi dealer, eBAY or web vendors like http://www.clairparts.com/

This is a super ez mod consisting of the followoing steps that (according to Audi's instructions) must be performed in this order:

1. Install the tuner in the space provided on the left side of the boot area.(FIG 1) 
• lift plastic cover, there are 2 clip holes. A small screwdriver or a key will open easily. (Arrows in FIG 1)
• Locate foam wrapped cable ends (FIG 2)
• carefully clip zip ties from factory and unwrap the plug ends
• remove bypass loop plug from CAN cable (FIG 3)
• plug cables into sat tuner (FIG 4)
• slide SAT tuner into the mounting bracket. Fit is very clean.
• secure with 2 very small zip ties (FIG 5)
2. Remove passenger side kick plate by door and connect CAN bus plugs
• Carefully remove kickplate cover - Typical VAG plastic part with metal clips. Requires a firm tug in strategic places to remove w/o breaking anything. Take it slow and be careful. The plastic above the top clip needs some care to remove without stressing the plastic (FIG 6)
• locate cables, they are wrapped to exisiting wiring bundles with masking tape
• remove tape, plug CAN connectors together (FIG 7)
3. Turn on car, press SAT button on stereo and tune to preview channel
• Go to SAT vendor website and activate your SAT tuner, make sure unit is on and receiving signal when you do.

That was all I had to do!

You will notice no mention of VAGCOM, the official line from Audi, says you will have to use VAG COM, but I did not. I installed a Sirius tuner in a BOSE, SAT Ready, Non-Nav factory HU.

For your reference I am posting what I have been told needs to be done with VAG COM.

1. Plug the CAN compliant VAG COM ito the A3 8P Dash port
2. Select Option 56-RADIO
3. Select Option 10-adaption
4. Enter Channel number 99
5. It will show -1- Slide bar to -0-  Remember to Save Settings
6. Display on VAG COMshould say that Value -0- was saved.
7. Back out of the setting. Radio/SAT receiver should now operate.
8. If you still see "No SAT Radio" when you hit the SAT button, you need to recheck the wiring. All CAN connections must be verified.

I plan to borrow a VAG COM to double check these settings, but I have been working 100% for a week without any VAg COM modifications.

The most important point? Factory SAT tuner install @ dealer = $700

My home install - $365