I entered Mexico by air and received an entry stamp and an FMM card, but am planning to leave by land. I'm going to fly into Tijuana airport and take the Greyhound bus from there to north of the border.
From what I gather, the bus will stop at the US border patrol or immigration station at San Ysidro but as far as I know there is no stop at the Mexican immigration station.
What is the procedure in this case for turning in the FMM card and getting an exit stamp in the passport?
I don't want to have any problems returning to Mexico in the future.