I think I know what you are thinking, but there is no sign of water lodging in the well under the battery.  I would be surprised if there would have been because some years back after finding water there I cleaned everything out and then put stn stl mesh around the underside of the battery to protect the drain hole from crud.  Today I have poured water in the well and it drains freely, so where did the water come from?  No sign of  damp under the passenger door.  The car is normally kept in the garage and when the water got in it was outside and raining 'cats and dogs' - 2" of rain in 6 hours.  Perhaps that sort of deluge will not happen again, but next week it will be outside all week and rain is forecast.  So, in short, if rain is not getting in via the pollen filter housing, where might it have come from? 

Read the stickied water ingress thread at the top of the page from start to finish, just because the drain under the battery is working water can still enter the car through the pollen filter housing if it has not been sealed correctly. Other places are through the window regulator panel you will notice the sill being wet after rain.

Edited 22 September, 20214 yr by gfinneran