tubular lock hood pins - lock cover??

[tastyratz]

so I picked up a set of these babies for my car:


and I love it, its much cleaner and overall nicer than a regular hood pin plus has security for those of us with alot under the hood.

Unfortuanately its also an open cylinder facing skywards and exposed to the elements. Something tells me that these tubular locks will fill with dirt grime road salt rain and misc nasties that will quickly lead to their failure. I was hoping to find some sort of like a plastic snap in cover for this...

Anyone able to point me in the right direction? Something I can just pop in and out, and its cheap/easy to replace when some asswipe walking by my car decides its fun to just pop the thing off.