A common problem I have seen on many BMW’s is a water leak due to a failing vapor barrier (also known as sound insulation). This is often misdiagnosed as a door seal or sunroof drain problem. It is normal for water to enter the outer door skin and drain out. When the vapor barrier separates from the sealer water runs over or under the lower door sill and fills the footwell with water. This video covers a lot of topics including tips and tricks to not damage the wood trim during removal. If you need to remove or replace the door panel, wood trim, window switches or access the window regulator this video will help.