[greatbm]

Water will always enter the doors due to rainfall or washing car the barrier is more a vapor barrier to protect back of door cards. Water should drain from door drains before even reaching the barrier seal level which is quite a few centimetres from the bottom of door, door drains can become blocked preventing drainage and you may hear some water sloshing around in doors. Door drains should be at the bottom corners of each doors, I have check mine are clear with a long plastic cable tie.

From what has been said you would expect the dampness to be near the door if a defective barrier before migrating to the centre. Seems strange only centre damp that is why I mentioned my problem with defective windscreen seal.