I have an '08 M-B S550 with a factory installed sat. radio. It has worked perfectly until 4 April when it "magically" began a Sirius update. I spent over 90 minutes on the phone talking to the call center in India trying to restore my service. (I receive 5 channels 216-220...that's it.) Finally, in desperation I sent an email. I have been told that Sirius is aware of a problem with factory installed satellite radios in M-B vehicles and that I should "check back" to see what happens with a fix. Incredible. I have Sirius in three radios (one other M-B and one in my house). I've been a customer for about 6 years and it it MY responsibility to restore my service once they have a fix for my car. All of you would get a laugh if you read the two emails I've received from their Customer Service people. It seems as if their attitude is, "if you didn't have a Sirius radio in your Mercedes Benz you wouldn't be having this problem." Very disappointed.