This is for VW Newbies like me...
I know in this day and age leaving keys in IGN for extended periods with IGN off is uncommon. However I have cause to do so at a particular location and I can imagine others doing so in a lockup garage. The manual even recommends against doing this for extended periods because eventually it will flatten the battery. But another trap I have noticed with my MkVI is that the Auto headlight setting will activate parking lights at dark even with the keys in and IGN off. So battery will of course flatten much quicker in this state. Turning headlights from Auto to Off fixes this, if one must leave keys in and IGN Off. Still it is a trap for young players like me and I thought is might be useful info to other VW newbies like me. My Toyota Auto lights are only active with IGN on.