How to Attach a Piece of Loose Molding -- Any Adhesives to Recommend?

I have a piece of loose chrome molding on the rear quarter panel of my car. It will not stay attached with molding tape; I need something stronger. Can you help? Thanks!

The usual cause of failure of molding tape is insufficient preparation.  Everything has to be smooth and clean.  It also has to fit well.  Nearly all failures are due to poor prep.

The molding is not flush on one end with the body. It is slightly curved. The molding clip is missing. There is not a flush surface on the trim – more like a ridge on the end. I think I need something like a piece of clay or something that I can mold to the shape under the chrome piece and then attach — I don’t know …

There are several waterproof adhesive sealants that might work. Check out two-part epoxy resins at the local hardware store. Look for one that is made specifically for the type of surfaces that will be mated. Most two part resins are sticky enough that once used, you will never get these parts apart again. So use them carefully. If you want to try something that isn’t so permamant, you could try a hot glue gun. Mistakes with a hot glue gun are easy to undo.

Prep properly as Joseph_E_Meehan stated. Use double sided butyl tape.