Soooooo....I wired the XM adapter in the boat to the ignition (swithed) just like the stereo so that it turn off when the ignition is swithced off (once again, just like the stereo). Well, the stereo has no trouble (doesn't miss a beat) when I swithch the ignition from run to accessories (gotta do it fast), but the XM shuts down. Is there any sort of momentary power storage device (like a cap) or whatever out there that I can use to prevent this short of wiring it to hot and having to remeber to shut it off at the end of the day?.