In the article -http://www.fiberglassics.com/restoration/restoring-gel-coat I found the comment:
Never use one-step cleaner waxes for the same reasons mentioned above, though to a much lesser degree. One step cleaner waxes use solvents to “clean” the surface and oils to provide a false gloss to the surface. When the wax in the product wears off, (which it will soon), the result will be similar to the scenario with Penetrol.
to be interesting. I have been using Meguiar's One Step Cleaner & Wax which might explain why I tend to have to wax several times a year.