One of my staff struggled with a VW when looking for a battery drain, He used to leave the doors wide open but with the catches closed so that it thought the doors were shut, he used a digital multimeter connected in series with the battery negative lead. ( We never moved on to scopes for this procedure )

He spent hours trying to find the drain and kept checking and rechecking but could never find the drain, He then opened and closed the doors and locked it up and went for lunch and within a few minutes the vehicle had gone to sleep.

So, rather than just making sure that the doors are latched, If the ignition has been turned on and off, Make sure that you open and close a door.

I am not sure how long it takes them to go to sleep without opening and closing a door but it was a long time and it can catch you out when you are working between jobs, pulling fuses and trying to find a fault in a reasonable amount of time.

H.T.H Tony.