I agree with Steve, unless you are living her permanently you don't need one. I've been here for 5 years and never had an issue, in fact I was parking a rental car Saturday night in Resistencia when a dumbass drove his moped into the driver's side door. The local police handled it all well, they had never seen a license from Washington state and were very curious about life in the US and how I ended up in northern Argentina after they had taken down all the details of the collision. Avis seems to be handling the accident calmly as well, although things probably won't be completely resolved with their insurance for a month or two. Of course the idiot who hit me had no helmet, shoes, license or insurance, and the moped he borrowed had no insurance or registration. He didn't get a ticket either, that surprised me but I think the police felt sorry for the poor schmuck who appeared to not be doing well economically.