Only guessing.
First do you mean INSIDE the door if so could be the window rubbers distorted letting in water between glass and rubber in one spot. Also check the bottom of the door see if drain holes are blocked, I had a Ford and the door drain holes were covered with membrane spray paint so water could not get out. Meanwhile try approaching Vauxhall tech service. www.Vauxhall.co.uk click contact us at bottom of page.
bob, November 2009
