How to Deal with Wind Noise and Water Leaks from Around a Vehicle's Door
16.06.10
If weatherstripping tears, becomes separated from its guide, or wears out, a water leak and/or wind noise from around a door may occur.
To determine whether noise is coming from one of the doors, use two-inch-all the way duct tape to seal the seam between the body of the vehicle and one of the doors. Drive the car. If the alarums has disappeared, the weatherstripping around that door should be treated as described below. On the other hand, if the wind babel is still there, strip off the duct tape, seal another door, and repeat the test.

To determine whether faulty weatherstripping is responsible for water leaking into the vehicle, aim a garden hose at the door nearest the spot where water is found. Sentiment about three feet away and spray the seams between the door and the body for at least 15 minutes. Confirmation to see whether there is water in the vehicle. Then, move on to a section that hasn’t been sprayed. You have to be patient. It can take a while for water to work its way into the vehicle through a gap in the weatherstripping.
Source: Motorward (blog)