Q:

Temporary windshield seal fix

I have a BMW E46 coupe with a water leak. I believe it to be a bad windshield seal, see the attached pic: 

Is this likely to be the cause of the leak?
What can I use as a temporary fix until I get a chance to get a new seal? I was thinking black outdoor silicone 

A:

Black rtv silicone or any glass sealing adhesive would be fine for a temporary fix. The key tip I can give you is:

Clean the surface well. Use isopropyl alcohol or mineral spirits, even just plain soap and water works. 
Dry the area very well. Using a heat gun or hair blow dryer can aid in this process by displacing the water.
Safety. Ventilated area. Gloves. Wear them. You'll want to press much of the material into the areas needing it.
Use acetone, mineral spirits, brake clean, etc to remove any excess material.

Suggest you go for something quick drying that is good in low temperatures if you're in a cold environment or have harsh Winters.

