The news is slowly trickling out now about the compulsory/ mandatory supervision of ALL (not some ASEAN) vehicles that wish to enter/ transit Thailand.
In a few weeks there will be an official announcement by Thai DLT of this mandatory supervision requirement.
What we think will happen (this could change some assumptions here)
1. Announcement before the end of 2016 by Thai DLT of most foreign vehicles (some ASEAN no) needing to be supervised by the sponsoring Thai tour company for the whole duration of the foreign vehicles time in Thailand.
2. Once announced, there will probably be a grace period of around 2 months, for permit date entry applications, that were lodged with DLT before the new law announcement, allowing them to enter under the old permit regulation (Grandfathered). Even if your permit application was lodged before the new law announcement, if your requested Thailand entry date for your permit, several months in advance, with the cut off, we think it looks like you will fall under the new law and need to be supervised by the Thai tour company. Be ready for this shocker (maybe).
3. By the end of 2016, the permit issuance will be handled by the local province DLT not Bangkok head office DLT any more.