I did my homework prior to our trip and found that my AAA auto insurance did not cover us in MEX. I did find out that if you use your Mastercard/Visa you are most likely covered by their policy feature but ONLY if you decline the CDW offered by the rental agency. It covers comprehensive, collision and "loss of use" for the rental agency but NOT liability. But....you should check the features of your own card.

What I was surprised about however is that Liability Insurance is mandatory and not in your rate quote from your US car company (we used National). It was never mentioned. I was on notice because it is a little bit of a madhouse at the airport and both Mexico and car rental co.'s in general are notorious for ripping you off. But, I looked it up and it is accurate.

I'm unsure if it is a flat rate across the board, dependent on the rate (%) or make/value of the car you are renting. We had a minivan and it was $10/day additional.

I wished I had known this info before my trip. It would have saved me some concern both before our trip, when I was trying to figure out how to get Liability coverage, and on our arrival.