How in God's name is this supposed to go back on??? I've tried clamping itself back on using the molded sides of the trim but no luck; it isn't a solid fit. It hasn't totally come of, but the back 1/4 length of the driprail has come off of the railing on the passenger side of the car. Any suggestions would be greatly appreciated.
Here's how I did mine. Need two people. Second person simply holds the molding in position while you snap it on. Just snaps on, you know? I took a 8" long 2x4 and covered it in several layers of soft cloth. I wrapped it tightly on the 2x4 and then stapled the cloth. Use the unstapled side only to install the molding. Starting at the rear of the drip rail place it in position after lining it up so you know where the ends will be when its installed. Use the wood block as a hammer to drive the molding on. Note that it installs over the top of the drip rail and snaps on at the bottom. Once the rear part is installed, 12" or so, then have the second guy hold it on with his hands. Steady pressure is all that is required. Work forward with the 2x4 hammer until you have the molding completely on. Once its completely on, it will remain on. Note that if any of it is loose, the entire length will pop off immediately.
Problem areas:
If the drip rail is freshly painted, you may have to sand off the paint and reprime the metal. Its important the drip rail be clean and the painted surface thin and uniform (no thick paint). The drip rail does not need any paint except primer where its not exposed. You'll be surprized how easy it goes on when the drip rail is clean on the areas where the molding covers it.