The countries listed here have a Toyota dealer:
http://www.toyota.co.jp/worldwide/toyota/index.html (remember to go through the different tabs for Americas, Europe, Africa, Asia&Oceania)
Who's missing? Off the top of my head: Moldova and Vatican City in Europe; Paraguay in the Americas; Afghanistan, Laos, Cambodia, Myanmar, North & South Korea in Asia&Oceania; Libya and Cote d'Ivoire in Africa. I'm certain that I'm missing others...
But don't be surprised if used Toyota vehicles are driven/sold from one of these countries and brought into others, though.