Follow the tracks somebody else has already ridden?
Lots of Crazyguy journals cover pretty much the same route down Baja, ferry to Mazatlan, overland to DF. You can do site searches on individual cities to help dial it in and read what troubles and triumphs previous bikers have experienced on each section of the way. You don`t need to register in order to get access to all the great info....
...but if you DO register, you can post your own tour journal and help out the next guy
http://www.crazyguyonabike.com/doc/l...octype=journal