What is the best adhesive to use for the ttop weatherstripping? I see some saying the 3m window ribbon stuff and others the 3m strip caulking.

This is the stuff you want

3M Weatherstrip Adhesive

JamesC

The 3M stuff Tony listed is what the factory used and what most people use. I used it on the bottom channel of the ttop weatherstripping and also to seal up the center bar. I then used the 3M windshield caulk to seal the top channel (the part that you see when you pull the weatherstripping away from the body with your fingers). I have had no leaks, but my car has only gotten wet 2 or 3x since I replaced mine 2 years ago.