This is from a detailer's website I was looking at:
Q. Do you use natural carnauba wax?
A. Rarely. Perhaps on very sensitive surfaces. Carnauba waxes are pretty useless as far as we are concerned. They have zero UV protection, very little protection from the elements that weather and driving conditions cause and are very, very overpriced for what is in the jar. They have a "large" molecular structure when they bond with paint. Most contaminants and problematic substances (bird-droppings, acidic rain) have smaller molecular structures and simply penetrate carnauba. (Its not quite that simple, but that's a brief explanation!).
Does everyone agree with this?