:
Mexico Tourist Card You supposedly receive an email with the completed form. In the FAQ's, it does state that if you don't get the email, you should fill out the form again and then download it when given the option.
I have copies I printed when I could find them, but I may try the online FMM - going to Cabo in a couple of weeks.
DO NOT USE any site but the official MX sites. Who know what the scam sites are doing with your info. It is completely free from the MX Gob!!
FMM Card (Tourist visa):
Instituto Nacional de Migración - Forma Migratoria Múltiple
And you can do customs, one per family, but Cancun does not want them and I think Cozumel is moving there too. if you do it, choose Cancun as the office then Cozumel as the checkpoint if flying to Cozumel.