I haven't looked in a long time, but I believe a valid passport and their driver's license from their country must be together. There's an ID/License book that comes out every year that lists all of the countries that the US honors. Every time I've run into this, it's been pretty obvious that the genius was unlicensed. Usually either the car was registered to them with a local address (which should be a big red flag) or they didn't have a valid passport. I also ran into those "international drivers license" BS cards that you can print off of the internet a couple of times.
