Do a web search for RV decals, graphics, or wraps.
"Beyond full sized RVs, trailers and campers can be wrapped as well to match their original design. Like RVs, the decals will often peel before any of the original paint shows any aging, so a simple custom cut decal job will restore the trailer or camper back to its original shape."
This is the link from the above quote . I know nothing about them, so this is not a recommendation.
http://www.coastalcreative.com/product/rv-decals-wraps/