Perhaps the list below would be of some help - its copied from the Alliance Internationale de Tourisme website. I believe they have overall worldwide resposibility for Carnet's. I've also found Carnet's very confusing, but there is a lot of info on their website.
COUNTRIES IN WHICH THE CPD IS REQUIRED (1)
Benin, Bophuthatswana, Botswana, Burkina Faso, Cameroun, Central African Republic, Chad, Ciskei, Comoros, Congo, Egypt, Gabon, Ghana, Guinea-Bissau, Ivory Coast, Kenya, Lesotho, Libya, Madagascar, Malawi, Mali, Mauritania, Namibia, Niger, Senegal, Somalia, South Africa, Swaziland, Tanzania, Togo, Uganda,Zimbabwe.
Argentina, Brazil (3), Canada, Chile, Colombia, Costa Rica, Dutch Antilles, Ecuador, Jamaica, Mexico, Paraguay, Peru, Surinam, Trinidad & Tobago, Uruguay, Venezuela.
ASIA & MIDDLE EAST
Bahrain, Bangladesh, India, Indonesia, Iran, Iraq, Japan, Jordan, Kuwait, Lebanon, Malaysia, Myanmar, Oman, Pakistan, Qatar, Singapore, Sri Lanka, Syria, United Arab Emirates, Yemen.
Belgium, Denmark, Finland, Greece, Italy, Monaco, Netherlands, Turkey.
Australia, New Zealand, Vanuatu.
This list may contain errors due to changes in national legislation.
In certain African countries, the CPD is not officially required, but is often used to facilitate temporary importation.
In Brazil, the CPD is not required for vehicles entering by land routes, but it is required for vehicles arriving by boat.
In these European countries, the CPD is required only for certain categories of vehicles. The CPD is not required in these countries for private cars.