I have a strange problem that has only recently appeared.

Seems to be water getting in somewhere around the offside rear door on my signum.

when you open the door, you can see water sitting on top of middle of the
bottom rubber and the plastic bit, the door card is also wet up to a certain point, and the floor also feels damp.

Have checked the obvious things and cant see any holes or damage to any of the rubber seals, removed the door card and there is no sign of anything coming from the other side of the door, as the door card is dry along with the plastic sheet.

Have sprayed water around the door and it doesnt seem to be coming in anywhere, only appears when you have driven it in the rain.

Not a major issue just an annoyance i would like to sort
Any ideas???