Mine fell off long ago...
It would only provide the most minimal protection from debris, etc (as it simply falls out if you look crooked at it) so I considered the loss to be unimportant...especially at $30 to replace. Usually, that kind of stuff would really bother me and I would replace it, but I just didn't see the point because it's such a stupid design. You would probably be better off putting Duct Tape over the hole...would offer just as much protection...would last longer too.
If you can't tell, I'm slightly bitter about the stupidity of the design.
