If it's painted, will it also be clear coated with quality material ? If not, it's for sure going to need to be waxed often, and if clear coated, IMO, still should be waxed.
My Titan horse trailers are painted but not clear coated, so to be kept looking decent, I've had to wax them.
Which is of course, the same amount of work as waxing a filon trailer.
The filon trailer I'm sitting in right now is coming up on seven years old and still looks good. Sit's outside all the time. Get's waxed two or three times a year. The decals are fading however. They are holding up, but they are fading. I wax right over the graphics with the rotary power buffer.