Under Mexican law, motorists are required to have insurance, or "proof of financial responsibility", in the event of an accident, even if you are not at fault. As a foreigner traveling in Mexico, the only way of demonstrating this financial responsibility is to have sufficient real currency to cover damages, or an insurance policy from a Mexican company. U.S. or any other non-Mexican insurance does not cover your liability for potential accidents, nor does it fulfill the basic requirement for insurance according to Mexican law.
Best insurance I've had so far
Use this Insurance Every Time I go to Baja .If you call them they have good service or you can get...
Check them out - best place to get Mexican Insurance before you leave for your trip/vacation