I am not sure how to use this site so please have patience with me. My 2009 Cabriolet has developed a strange problem. When parked in my driveway, it will occasionally self-start the alarm and flashing lights. My mechanics thought it was the plug-in adapter which was drawing power, draining the battery and setting off the alarm and flashers. I picked it up and brought it home and found that this was not the case since it happened again without the adapter in use. Does anybody have any idea what may be going on here?