I recently changed the gear oil in the CJ and noticed my diff covers are getting pretty beat up, so it's time for some protection. I was wondering if anybody had any experience with the Warn differential skid plates. I was thinking about them, mainly because the local store carries them and I wanted to save on shipping. My main concern is that from the catalogue they look more like diff covers, than actual skid plates. Does anybody know if they just go over the cover, or if they also cover the bottom and go around the back, so I can actually slide over obstacles? As an alternate, I'm thinking about the Rock-It differential gliders, anyone use these?