Yeah, my wife and I had the same idea. We don't want people to know that we're "FEMA trash," even though we just graduated from "pop-up camper scum."
I found some extra-wide pin stripping tape (oxymoron) at Advance Auto Parts. Think we'll do some gradient stripes on the sides, you know, fat to thin.
A sign company can cut you out some designs. Swoops and slashes ought to be pretty easy for them to draw on their computer. I've installed vinyl lettering and signage on a couple of trucks and a cargo trailer. It's frustrating enough on a flat surface, but god I image a corrugated surface is going to be a ...
Use plenty of soapy water when installing.