Check out the April 2000 issue of Motor Trend in an article named "Paint Care Myths
and Reality"
I am direct quoting here:
Motor Trend question "A wax made of 100 percent carnauba is superior to those using
lessor amounts?"
Answer by Mike Pennington, director of training for Meguiars "Carnauba wax has been a favorite among car enthusiasts
for years, but don't believe that any wax is made of 100
percent carnauba. As the hardest natural wax known, carnauba is much too hard to apply
directly to automotive paint. It comes in bricks that must be melted and added to a
company's formulation. If a paint protectant advertises "pure carnauba," it means the part
of the formulation that is carnauba is pure, not that it's 100 percent carnauba. According
to Pennington, todays synthetic polymer technology actually provides better protection than carnauba"
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I think most of us here will agree that a quality polymer will retain gloss longer, bead water longer, and stay slicker longer than a typical carnuba.