Thanks for this very informative post.

Today I was surprised when I found out, that most of these 10mm bolts holding the oil pan on the engine block were in fact loosen quite a bit. This way I could trace back a lower oil leak to its source. And even though the car is not used offroad or racing.
My advice is to definitively check and tighten these bolts, especially those on the forward part of the pan. Quite possibly, leaks might often be associated with part of the engine IMO.

Best wishes
JAzz