A portion of the weatherstrip on the passenger door has torn right where the side mirror assembly meets the window. The only solution I see is to glue down the flap but I'd appreciate any other suggestions or suggestions on adhesive to use for the rubber to plastic.

I've attached a few images that show this better than I've described.

Thanks,

sdl13
2006 Roadster

 

Nothing is going to hold for the long term. The only permanent solution is to replace it. It's pretty common for that piece to split as I've seen it on many Zs, including my own. When it gets bad enough, I'll replace it.