There is a friendly discussion going on about Mexico RVing over on
http://rvlife.com/rving-in-mexico/. It has a couple of the expected "You're crazy to go to Mexico" posts but on the whole everyone is civil. Here is my contribution.
We have spent six winters (5 months of each) solo RVing in Mexico. We travel alone because we like our own schedule and change our route several times each year as we talk to people along the way. If we like a place we may stay a month, if the weather or surroundings is not to our liking we may move on after a day or two. We feel safe and confident enough that we do not need the security of a caravan or even a travel buddy. We have RV’d in every State of Mexico. We have had three relatively minor traffic accidents, only one of which involved another vehicle (he ran into us) and all of which we were able to drive away from. All three were fully covered by our still reasonably priced Mexican Insurance (San Xavier).
We drink bottled water which is cheap and easily available at every OXXO convenience store in sizes ranging up to 20 litres. Mexicans don’t drink the tap water and neither do we We spend pesos which we get from bank or large grocery store ATM’s. We would never show disrespect by asking Mexicans to take dollars. Visitors to the US or Canada do not ask us to take their national currency so why should we be different? How would you react if a visitor asked to pay for his hotel in the US with Euros or Yuan?
The advice in previous posts is valid. Don’t travel at night or hang out in late night bars. Do not associate with the drug trade - Ever! You will end up in jail or dead.Basically we follow the same guidelines we follow at home. Be aware of your surroundings, be respectful and if something does not feel right, leave. We are always back at the RV early, usually by sundown.
If you want to travel on libre (free, no toll) roads use common sense. Follow a bus or truck as they know where the topes (speed bumps) are. By doing this you can save a lot of money on tolls but keep your speed down, these roads are often rough.
Don’t be afraid to eat at street side food stands, In general they are cleaner than many/most greasy spoons at home and you will find some wonderful, reasonably priced food there as well as a chance to get close to the locals. Take a cab downtown, grab an outside table at a restaurant, order a coffee, a drink or a meal (or all three) and watch the people and families interacting with each other. It is guaranteed to be one of the memories you take home. Let the Mexicans practice their English on you while you try out your Spanish on them. You will make instant friends. These are the only times we violate our rule about being home early, and even on these occasions we take cabs and are never out past 9 or 10 PM.
Don’t be too concerned about not speaking Spanish, you will get by. I would suggest learning to read a menu or at the very least, carry a pocket size Spanish dictionary so you can order a beer or eggs and know the difference.. In a situation where nothing on the menu looks familiar just point at something someone else is eating and ask for the same. Everyone will have a laugh and you will get a good meal. Don’t worry about the cost, it will be less than you expect. Most Mexicans can speak at least a little English and as soon as they see you try to speak their language they will meet you half way.
The best advice I can give you is,this, be respectful, you are in THEIR country!