I installed Sirius in my wife's 2005 S60 and hardwired everything in. I have the 12v tapped into the fuse box but as far as I can tell there isn't a spare power supply on the accessory switch. Is this hidden somewhere or are the two always hot aux. 12 volts the only choice I have? I'd like for my Sirius to turn off with the key instead of having to do it manually. Thanks in advance.