19 hours ago, jimster said:

They use numbers for the characters after the 26th Thai alphabet, as there are only 26 characters in the Latin alphabet, but 44 in the Thai alphabet. For example, the 27th Thai character is "1", the 28th is "2" and so on.

The system for making 'latin' plate for going to Malaysia which is white letter on black background on stickers seem a bit arbitrary, seem to go for letter with similar sounds instead in some case, or capital letter for the first 26 then lower case from 27th letter onwards has also ben seen, followed by three letter abbreviation of the province name

On 6/15/2018 at 1:50 PM, Kinnock said:

Thanks for this.  So perhaps it was a new model in the C-HR range out being tested, or maybe a pre-launch model still running on the Test Car plates, as the C-HR has not been out long?  Interesting info in this thread - and a final answer.

I am quite sure that it's used for models not yet homologated by the DLT, i have seen few of these plates mounted on cars covered by thick black wrap used by test vehicles all over the world. 

 

A singularly high concentration of them is in the evening at the Shell gas station on the Bang Na - Trat after the intersection with Srinakarin....