Mine was activated by my dealer. I'm guessing this is done by the detail shop within a day of delivery.
My 6 month trial quit about 6 days late. I called Sirius to re-up, and asked if they had any deals. The rep asked if I had a code. (nope) I asked again if he could give me a deal. (nope)
One week later, I got a 50% off coupon in the mail
I phoned immediately to protest. The friendly CSR said "No problem, sir. The 50% will be refunded to your CC within the week."
And it was. :happy feet: