Clean and de-grease it well, and bond it back on with a good quality silicone RTV. It will help if you can rough up the joint surfaces a bit. The advangage of the RTV is that is is Flexible and will stand up to the vibrations passing through the car. Most Glues will fail as they are usually quite brittle. You should be able to buy it at your local Auto DIY store.
Make sure it's a dry day!!!!!
Last edited by Pat.w; 9th December 2007 at 02:57 PM.