Doesn't the SL already have the bluetooth?
Maybe that's the preferred package. Anyways, I asked this kind of question A LOT when I was shopping for my cube, and I got a different answer every time. The final verdict is that they might be able to install the bluetooth if the buttons and such are already there. i.e. if it only requires another chip, they can probably install it. If your SL does not have all of the hardware already installed though, such as the microphone, they propably can't help you. If you really ant bluetooth, I would suggest buying a good earpiece bluetooth that definitely matches up with your phone. The pairing with the cube has been an issue with some people.