Since I'm not a paint expert, I need to ask: Besides not creating a mess, is there a major advantage to painting outdoors? I mean, the cab, I assume, will be indoors when it's done. Why not just bring it in early, lay down some plastic (and make a plastic enclosure too if you don't want dust everywhere), crack a few windows and paint it then? We all paint our walls/ceiling at some point, why not the cab?
I was originally going to paint outdoors but I envisioned too many problems. Besides weather (humidity and rain), there's the chance wind might blow debris onto the freshly painted surface or a bug will decide to rest in it.