Originally Posted by Rather Dashing
Sat Prep has the wiring already setup for sirius but it does not have the receiver. You need to buy the receiver and the harness and either have BMW install it or do it yourself (but BMW still needs to upgrade your software apparently).
Don't know how valid the claim was, but I was told over at bimmerfest that you have to tap into the fiber optic setup. If the car isn't setup right for the upgrade you can render your car disabled until the SW upgrade is performed. Didn't want to risk it, so I had it installed at the dealer.