Steve,
Chances are the paint is distroyed. Once paint oxidizes to a point that it no longer shines on its own, the only way to get it to shine is to use a polish and wax. As you have seen, though, once the wax evaporates, so does the shine. Any detailing fix you apply at this point will be temporary. At some point you will need to have the car repainted.
You can put off the repainting for a while by using a good sealant instead of your wax. A product like
Klasse AIO /
Klasse SG or
Zaino Show Car Polish will provide a lasting shine with much better durability than wax. Of the two product, I think
Klasse is better on a poor surface. Both products can be layered for additional gloss and depth.
db