I disagree about Bali having a similar status as Puerto Rico or Guernsey. As you said, Bali is just one of 34 provinces of Indonesia (in fact, 31 provinces, two special regions and a capital region). Are we now looking for cars from Bengkulu, Lampung etc? We could just as well start listing cars from all 101 French départements, the 16 German federal states or the 50 US states. Which takes us to Puerto Rico that, as you might know, is not a state, but just a territory of the United States. Here your territory rule applies justly. Guernsey is a Crown dependency and it is not part of the United Kingdom, not even part of the European Union. It even has its own international licence plate country code, GBG.
After all, it is your game and these are just my thoughts about clarity of the rules.