Mine seems to have kept rust a bay somewhat. I've had it up in the air, looked most places (even front wings off) and it seems very good.
Obvious R places are rear arches, rear wheel wells where they join the floor pan.
What I did with mine was jack it right up and jet wash it off (during the good weather we had) then ran it around for a day or so to dry off properly, then waxoiled everywere underneath (there's lots of nooks) then white greased sprayed (motorcycle chain grease, nice n sticky) all bolts and threads etc.
Also when I've done anything on the car (like messing with the front bumper, adjusting door hinge) I've cleaned and treated all exposed areas.
A good idea also is to remove the side skirts, they seem to fill up with mud and dirt at the front end and it's a good idea to clean all that off so it can't hold onto moisture.