I am a fan of the ZEP floor wax system, but first you need to prep the surface. I recommend using a Scotch kitchen scrub sponge with a very mild abrasive, either Bar Keepers Friend or Bon Ami. It will be a slow process because you need to go over every square inch with light scrubbing. Odds are there is still some old wax on the RV. You also need to scrub that off using a dilute ammonia solution. If you take your time with the surface prep, you can then apply ZEP finish that will last and last. Mine is still going strong from 2015.
The Zep finish is easy to apply. You can use a sponge floor mop, but I did mine by hand. Lightly dampen an approximately 10 inch square rag and apply a thin coat. Make sure you do not get any drips and sags. The first coat or two will not look good. You will need to apply at least 4 thin coats. The Zep finish will prevent further oxidation, will give the RV a moderately good shine, will prevent the black streaks, and will last for years. Zep works so well I barely have to wash my RV. I do wash it about once a year and apply another thin coat of Zep.
Again, surface prep is important. If the surface prep is skipped or done poorly the Zep surface can flake off after a few months or years.
