Auto body repair & detailing: reglue astro exterior trim, chevy astro, rubber cement

Question
I have a 97 Chevy Astro whose fiberglass trim piece that attaches to the sliding door has come off. It had a piece of rubber between it and the door with a lot of grooves in it. There is some black stuff still on the door and I have both the trim and the rubber piece. I would like to reattach the trim to the door and have no idea what to use or how to proceed, but I am fairly handy.  

Answer
The black rubber stuff was a double sided rubber membrane.

Rubber cement won't take a hot day...so get your self some 50/50 two part cement...that ought to hold her.

Make sure to clean off any road grime...pull it our without permanently bending it to clean underneath.

You really don't want to do this twice...get some clamps ready beforehand.