We have always used Aero 303 instead of wax on our Escape. Last year, just before a 3,000 mi. trip that took us through bugs and pollen, I did an additional application of 303 to the trailer front and leading edges generally. When we got home, our usual washing with Dawn in a bucket of warm water took all the bugs, gunk, etc. off. The only additional work was a bit of paint thinner to take road tar off wheel well surfaces.
Not scientific (no controls to compare), but the pragmatic conclusion for us is, Aero 303 works.