If you're seriously worried about your security while traveling through foreign countries, there's probably nothing worse than a giant, lifted, and possibly tactical looking vehicle. To be frank, it says nothing more than "Hey! HEY YOU! LOOK AT ME I HAVE MONEY AND LOTS OF COOL STUFF INSIDE" so remember those problems you had parking your kitted-out hummer in Tijuana? It likely would not have happened if you chose an old Mercedes wagon. Seriously, no one is going to break into this car, virtually every single country in the world that you can visit is literally crawling with old Mercedes vehicles just like this one. Why? Because in the 1980's Mercedes-Benz engineering was at its best, and they built these cars like tanks—it's why so many of them are still running today.
The example we found, a 1983 Turbo-Diesel Wagon, is located in Phoenix, Arizona and the seller is only asking $4500 or best offer. That brings you a vehicle which gets upwards of 32 mpg that you can easily sleep inside of—or hell, ontop of with the factory roof rack. Even though it has over 200,000 miles—we're pretty sure it's still running great. Did we mention that you'll be able to get parts almost anywhere in the world for this wagon?
The seller does caution that it's a 30 year old vehicle and not to expect anything new.
If this one doesn't tickle your fancy, just check your local craigslist—you'll be sure to find something similar.