The following story was related to me by my friends from La Paz, Richard and Mary Lou Adcock, in the Spring of 1995. At the time this happened they were driving from La Paz to San Diego.
While on a straight section of the highway north of Santa Rosalia, Richard and Mary Lou were passed by a small "sporty" car traveling at about 70MPH. As this car was heading uphill into the beginning of a mountainous section, it suddenly began fish-tailing and then went off the road in a great cloud of dust.
Richard stopped his truck in the road and, with great trepidation, approached the remains of the car (the dust was just beginning to settle). His first sight inside the car was that of what appeared to be a large bag pressing against a body. As he reached the car, the bag was hissing and deflating - an "Air Bag Supplemental Restraint System!" The driver seemed to be the only person in the car, and was then starting to show signs of coming out of shock. He didn't know what had hit him.
The driver survived with only minor scratches, and was able to crawl out the passenger side. The car had gone end-over-end several times before landing right-side-up, and was a total loss. It turns out that the driver was a young man who had been visiting in San Diego and had rented the car there. Against the restrictions of the rental policy he had taken the car into Mexico, in fact all the way to Cabo San Lucas and half-way back. He had also not bothered to purchase Mexican insurance. It would have been interesting to have seen him returning to the rental agency with that tale, and no car!
Now for the important part of this story - Why did this accident occur? It turns out that there was a rock in the road which caused the driver to swerve suddenly and begin the fish-tailing which led to his going "off-road." The area did not have cliffs from which the rock might have fallen, and so one has to wonder about just how the rock got so strategically placed in the road.
It is my conjecture that the rock was placed in the road by a well-meaning truck driver. Sometimes the older trucks will have a break-down on a mountainous grade and, as a warning, the truck driver will place a large rock in the roadway some distance in back of the truck (rocks are plentiful and cheap, while fancy reflective devices are expensive). Once the truck was fixed, it seems likely that the driver forgot about the rock that had been placed in the road - and there it sat, awaiting its victim.Moral: Expect the unexpected!