Ending is not that happy

Home for them was a 8x8 concrete cell, the ending was beautiful as well as perfect, and happy too, imo.

Once they get used to drinking the local water, they're home free.

And if you really want to think about this, I wouldn't be surprised if Andy couldn't acquire new IDs for both of them, perhaps as Mexican citizens who emigrate north legally if they missed America.

Oh, Mexico
It sounds so simple I just got to go
The sun's so hot I forgot to go home
Guess I'll have to go now

Americano got the sleepy damn eye
But his body's still shaking like a live wire
Sleepy "Señorita" with the eyes on fire
Oh, Mexico

It sounds so sweet with the sun sinking low
Moon's so bright like to light up the night
Make everything all right