I was searching the forums and noticed some horror stories of bad rust between the skidplate and frame. I have an 2006 wrangler and a rust free frame in the northeast. I lowered the skid plate and noticed some rust build up. I wanted to do this to make sure the bolts come out and the transmission mount bolts come off. I wirewheeled a-lot of the rust off and laquer thinned it clean. Did the same with the skid. I only had por 15 chassis top coat and nobody had the por 15 rust paint. I painted that on both surfaces for now, but in spring time I'll remove it again wirewheel the topcoat down and por15 the frame than redo the topcoat. The topcoat should hold me over for a couple months, looks better than rustoleum.
If you decide to do this and your jeep is older be careful with all those bolts, last thing you want to do is break one when you are trying to do preventative maintenance. It is worth it though. Took about a 2 hours to do and waited all night to dry. It is only 50 degrees here though.