Leaving Mexico

Usually when you board the plane they are only concerned that you have a Tourist Visa to turn in. I've never had them actually look at it closely. That may differ from airport to airport but I can't see the airlines acting as police about it.

it really depends on the airlaine, sometimes they check sometimes not. Anyway after 180 days in the country, you need to leave, so you don't get more days from any migration office. So either you take the risk or you go to Guate or Belize for 1 day or 2.
Anyway I think if you take the risk, what can they do? just charge you some money I assume. good luck.

The consensus among travelers is that the airlines, which have typically collected the tourist visa (FM-T) when you check in at the airport, don't care when and if you're visa is expired. I have left late several times, though not by more than a few weeks. Traditionally the airlines employees do not even look at the visa, they just take it and put it in a pile. Who knows if the Mexican immigration authorities go through the piles.

HOWEVER, the last time I left Mexico, in August 2006 in Mexico City, the airline was NOT collecting the visas. They said there was a new procedure. Instead they said I had to give it to Migracion directly. I went through security and immediately to one side was a counter/desk with a Migracion official. I was sweating, because I was running very late for my flight and because my visa was expired by a few weeks, but she spent a moment looking at it before waving me through. Also, at that point I was on an electoral observation visa, a type of temporary FM-3 used only for electoral observers. In theory me overstaying that visa could have been a little sensitive because of the semi-political nature of the visa and my activities, but the Migracion official either didn't care or didn't notice that my FM-3 was not the typical one.

So, it seems that if it is standard that the Migracion officials now collect visas instead of airlines, you could more easily be caught and fined.