Mel Gibson is an unnamed driver driving a getaway car full of money and a dying (and soon dead) accomplice being chased by the police very near the Mexican border. Rather than being caught on US soil, he intentionally crashes through a border fence into Mexico. The cops on the other side (who were also following along) while initially happy to hand over the two American nationals back, change their minds upon seeing the money. They decide to keep it for themselves and hush Gibson up by imprisoning him in 'El Pueblito', a notorious prison controlled by criminals. The rest of the story is about how our man gets his payback.
I say payback because if you liked Mel Gibson's highly underrated 1999 flick "Payback" (or the 2006 Director's Cut), then you will very likely enjoy Get the Gringo! While it does not appear to be officially related to Payback, Get the Gringo shares the same primary character & feel and it is presumably not being marketed as such because the makers do not have the rights to do so. That said, even though they share many similar attributes, the "sequel" is nowhere near as tight either in plot or direction as the original.
The plot in particular is distracting at time due to some, IMHO, gaping holes. The direction is a little too ... Hollywoody, and lacks the dark terseness of the original. All that said, however, the movie was an enjoyable ride and the 'El Pueblito' setting was refreshingly unique! I recommend watching this, especially if you're a fan of the original. If you haven't watched the original (or the DC), I envy your forthcoming triple bill experience :)