Originally Posted by Eastbay1K

You are probably SOL. The odds of a Chile rental car going to Bolivia and it turning into a permanent one way trip is quite high. It isn't "not high" for Argentina, either. It would be absurd for these agencies (as a viable business practice) to rent you a car, and permit you to drive to Bolivia, without having a deposit for the entire value of the car.

I am also going to give you some advice you probably won't like. The altitudes you will encounter, and suddenly ... will hit you like nothing you've ever experienced. I'm not sure of the maximum altitude on that particular route, but once the headache hits, it will be too late. The best thing I never did was rent a car in Arica for a drive into Lauca National Park, which was sea level to 4500m in a few hours. The tour van driver kept almost nodding off periodically, and he does that every day for a living. You'll also likely have a lot of large truck traffic. You may also have large gaps of no cell communication (and if you have it, just voice, no data) should anything occur on your trip.