I can’t seem to emphasize this enough…
A fender-bender accident is about a million times more likely than having problems with crooks on the highway. The odds of a traffic accident in Mexico for travelers is roughly the same as in the USA. Travelers do not drive at night and are much more conservative and alert in Mexico. Boiled down, I hope this gives you perspective on just how improbable trouble would be.
Organized crime focuses on tractor trailers loaded with goods. My standard joke is “What’s a crook going to do with a whale-size “casarodante”? It can’t be hidden, the furniture inside is useless for a house, the engine and drive train are about as much in demand as a ’92 Yugo. Years ago two motorhomes were carjacked near Cd. Victoria on the Atlantic side. The vehicles were recovered, and the crooks apprehended. One of them remarked caustically to the arresting cops “Stupidest thing we ever did. No money. Nothing valuable inside and we could not hide them”. Rumors travel fast in the crook community and the pair became victims of very rude jokes in prison.
Petty theft has ALWAYS been a problem in Mexico for tourists and Mexicans alike. Keep your compartments locked. Place valuable tool boxes together with other pricey items and then run a cable or chain and secure with a padlock. Bicycles should be padlocked to the rack. When away from the rig, draw curtains.
RV parks generally are safe at night, but petty theft is sometimes a problem. Cable lose items together.
Keep your gas tank topped off when parked for long periods on the beach. The school of hard knocks taught me it does not take much empty space inside a gas tank for an incredible amount of moisture to form and drop into the gasoline. Amazingly, two gallons of water can form in a month in an almost empty 100-gallon RV gas tank. Mexican gasoline does not contain alcohol.