I've heard a few claim they have waxed them for years with no issue but I was waxing mine one time and thought what the heck, wax it all. First thing I noticed was that the blue decals put a lot of blue coloring on my wax pad. So I was thinking that's probably not a good sign if it's pulling the color out.
Also, as another stated about the wax getting under the edges causing them to peel was my other concern as it's virtually impossible to get all the wax out from the edges.
Since then, I'm careful of getting wax on the decals and use Aero 303 instead. So far decals still look good after 5 yrs in the sun. Of course the nose is faded because it gets full time morning and evening sun.
Coming from the printing industry with experience in large format outdoor poster printing, the quality of the vinyl and UV inks used is a major factor in how long your vinyl lasts. Some RV manufacturers purchase the least expensive products that wont last no matter what you use if they set in the sun. My previous RV looked like it had dry rot on the decals after 5 yrs.
Walter and Janie Rogers
2012 Sundance 277RL
TV 2006 Silverado 2500 6.0