From what I can find that "passport" is only recognized, and required, by Laos.
There is extensive commentary on that "other" forum" concerning this subject, although some of it is questionable.
And the following:Every neighboring country of Thailand allows Thai cars to enter, just as Thailand allows cars from those countries to enter Thailand. However, there are different entry requirements and restrictions - Laos is the only one with a formal "automobile passport" requirement, meaning cars from Thailand (and Vietnam) require an automobile passport, issued by the land transport department in the respective countries to enter Laos. Similar, Lao cars require the same for entry into Thailand and Vietnam.
None of the other surrounding countries use the system. Entry into Malaysia is generally the most straightforward of all of Thailand's neighbors, but a translation of the owners blue book (for cars) or green book (for motorcycles) is required, as is a translation of the licence/number plate, in the form of a sticker with a black background and white lettering, mimicking Malaysia's number plate design.
Cambodia and Myanmar both have restrictions on which border crossings can be used, and/or how far a foreign registered vehicle (including Thai) can drive inside the other's territory. For the most part you can just show up with a blue or green book, for cars and motorcycles respectively and enter Cambodia, at the checkpoints which allow vehicles to enter (currently there are 3). For entry via the other checkpoints, more formal arrangements must be made in advance. For Myanmar you'll need to go on a tour otherwise you won't be able to go much further than the town limits, of whichever border town you enter at, even though you as a passenger could if you enter with a Myanmar visa, but the car won't be allowed to.
BANGKOK, 26 September 2014 (NNT) - DLT explained that the automobile passport is an agreement between Thailand and Laos, although new driver licenses can allow Thais to drive in all ASEAN countries.
The DLT deputy-general, Atsathai Rattadilok, said the automobile passport cannot be used among other ASEAN countries and can only be used in Laos PDR as the agreement is only between Thailand and Laos PDR.
Other ASEAN countries are not involved in this, although the new driver license will allow drivers to use cars in all ASEAN countries, including Indonesia, Malaysia, Philippines, Thailand, Brunei, Vietnam, Laos PDR, Myanmar, and Cambodia.
In case of any confusion, or if you have any clue which can lead to uncovering any deceptive practices, reports should be made to the license department at the Provincial Land Transport Office of Bangkok area 5, Tel. 02-271-8426 or Call Center at 1584 for 24/7.