I did find this extremely helpful. I am considering an attempt at making a gasket for mine. Possible cork, but an old bicycle inner tube would probably be better.

If you can advise - why does water get under there? Is it because of blocked drain lines? I notice that water is gathering there after I wash my car, or big rain. Not in a big amount, the trunk inside is quite dry. But, this thing which you removed - it can be wet where the trunk is closed.

shelling out for a brand new light to replace a rubber seal seems ridiculous.