in Mexico going north?
Are you driving north, from Mexico to the US?
Some guy in the US (won't mention his name, but he has driven an old Indian Roadmaster around the world ;-)) gave us a prepaid phone for the US, with 12vcharger etc, and it still has some minutes left on it.
I believe it is bad for our Karma to simply throw it away, so if you are somewhere near or south of Mexico City, we can meet up and you'll have a free phone for the US!
We might still have our National Park Annual card also...
just contact me at Far Away From Flakkee