before I saw your added comment below the first thing that came to mind is you've got water getting into the electrics somewhere, try and dry out the box the waters got in to and look to make sure it hasn’t got in to anywhere else. hopefully that will help most of the issues, I've had the 1.9 diesel and the same thing happened to all the electrics after water got in and things used to turn on randomly in the middle of the night like the alarm and the interior lights and used to drain the battery, maybe worth checking the batteries charge too after you dried it all out.