Programmer's Gambit

I then get called in to talk to four FBI people.
They’re very suspicious. The lead guy says, “We checked out your wild story. Amazingly enough, we found a few things that support your theory. We now have Dave and Fifi at the Mexico City airport with a few million dollars in US currency, usable almost anywhere in the civilized world. Now what?”
I say, “Dave is too clever to fly to where he wants to go. He also has quite a bit of fancy jewelry that Fifi stole from the drug dealer. They go where they can sell the fancy jewelry. A good place to start in South America is the country where they mine the best emeralds in the world. In all probability, you can check there and see if the jewelry has been bought.”
The FBI guy says, “Actually, you amaze me. We have done some preliminary work and there is a nice collection of fancy jewelry available in a South American nation. We have an agent in line to examine the stuff, but it’s likely that it’s what you claim. Now what?
I say, “Dave and Fifi are on the ground in South America, of which I know very little. They want to go somewhere anonymously. How do they go, remembering that at least Dave can speak fluent Spanish?”
The FBI guy says, “There are a couple of ways. They probably wouldn’t want to fly, even with false names it would be too easy to trace. They could go by rail or they could go by bus, pay cash and leave no tracks.”
I ask, “What if they have to cross a few national borders?”
The FBI guy says, “A few bribes and they’re past the borders with no record. South America isn’t generally an area of very rich people. Border security isn’t tight and a little cash money can grease the way past the guards.”
I say, “Dave and Fifi get to where they want to be. They want the good life. There’s only one place that they reasonably go.”
The FBI guy says, “How can you be sure that there is only one place?”
I say, “Dave and Fifi lived in San Diego. San Diego is a nice place to live. It’s a bit isolated and the job and/or business market isn’t first rate. However, one thing is the best in the United States and maybe in the world, at least among the best in the world. Do you know what that is?”
The FBI guy says, “Educate me.”
I say, “San Diego, in a typical year has day after day of late spring or early fall weather. The mornings are just cool enough and the afternoons are just warm enough. Do you know where you can find that kind of climate in a big city?”
There’s an FBI lady sitting in the background and she’s now grinning from ear to ear. She waits for the guy I’m talking to to guess and when he doesn’t she finally stands up and says, “Santiago, Chile!”
I say, “Of course, one of the very few areas of Mediterranean climate outside of the Mediterranean and the only such area in South America! There are other areas with Mediterranean climate but they don’t work either because they would check new immigrants too closely, they’re located in a war zone or they require a different language.”
The lady walks over to the head FBI guy, holds out her hand and says, “Pay up, sucker!”
The head FBI guy sadly shakes his head and says, “Live and learn.” He then pulls out his wallet and pays the lady a $20 bill.
The head FBI guy says, “Okay, the guy’s in Santiago Chile, a major city. He speaks fluent Spanish and he can fit in. Assuming, just assuming, he’s in Santiago, Chile how do we find him?
I say, “You probably don’t find him in Santiago, Chile.”