Locate leaks:
WARNING: This page is about a different car, the 2002 BMW M Roadster, 2002 BMW M Coupe, 2001 BMW M Roadster, and 2001 BMW M Coupe. However, it is still accessible from the selected car via links, so may be relevant.
- by spraying water underneath sealing lips
- with ultrasonic leak detector (sourcing reference: BMW Parts Service)
If necessary, seal leakage with appropriate nozzle.