Went to get the car out of the garage today, been away for the last 2 weeks, so not been run, and found the car dead! no lights nothing, suspected flat battery, so went to unlock the boot and can't get in, key won't unlock it either, i didn't think the boot lock needed power? Is this correct? Tried charging the battery via the cigarette lighter socket for about 5 hours to see if enough charge just to get boot open, but that hasn't worked! Any ideas how to get into the boot?