My brake light (the one above the centre of the rear window) seems to be leaking, is this a common problem? I removed the light and noticed it's coming in where the two metal clips are, also the seal was pretty much gone so I bought a new light unit, new seal included. But again it's still seems to leak from the same place. Admittedly it only really happens when it rains hard, but starting to annoy me immensely. Is there anything I can do other than firing a load of sealant up there?