Dirtboat,
Just left Puerto Penasco last week. Been staying at the Reef Rv. You can get painting done at the Playa Bonita Rv park and others, but I only know about the Reef. I'v known Jesus and Carlos, father and son painters at the Reef for about 10 or 11 years. They are honest, hard working painters. You can negotiate a fair price from them and they require half of the agreed price up front and the rest upon completion. In 2010 I had a Monaco Dipl 40 ft with 3 slides. Jesus and Carlos painted my rv. They did an excellent job. They started basic prep work at my rv site and then moved to a more secluded spot to finish painting and gloss work. I had my towed vehicle (2004 Envoy) painted the next year. Again a fair price and good job. 5 years later, we downsized and sold my Class A. Th new owner commented on how good the paint job was. I will use Jesus and Carlos in the near future as my trailer decals start to go bad. Can't comment on price because every job and requirement is different on what you want done. My rv took about 4 days to complete. My SUV took about 2 days.
As of last year, Jesus and Carlos have a designated spot in the park to paint rvs. If you go, the two are easy to find or Gus at the front desk can help you out.
So finally, would I recommend them? Yes. Do they do a good job? Yes. Do they work out in the open? Yes. I saw no bad problems from painting out in the open. Was their work perfect? No but its hard to spot imperfections and my old rv still had a great paint job when I sold it, five years after it was painted.
Hope this helps