3 coats huh....that sounds a little excessive but then again I've never lived in the desert. I've been using the Turtle wax ultra series with excellent results...Give it a shot and try to use a paste instead of a liquid. It's a little harder to remove but a paste tends to last longer and give better protection...
And if you find little areas you missed with this wax a few days/weeks later it comes right off with a rag.
And if you find little areas you missed with this wax a few days/weeks later it comes right off with a rag.