The cheapest insurance rate is for the 3rd party liability coverage, which is the only required coverage needed in Mexico. That coverage is for the “other guy”. It pays for any bodily injury or physical damage to their car, that you have caused. It is similar to that which most, if not all, U.S. states require when operating a motor vehicle in the U.S. Those rates generally start at around $ 4.00 a day for the lowest liability limits. NOTE: recently, each Mexican State determined it’s own minimum liability limits, which range from close to $5,000 U.S.D.$ to $540,000 U.S.D.$…that’s right, in U.S. Dollars! You can see the exact requirements for each Mexican State by clicking on this link, and go to the State you are traveling to. Please also note that you might be crossing from one State to another, and thus encounter differing liability limits.