Also, even if you have the JCV file, it will only work on the unit that supports JCV,
such as the nuvi 215w in Thailand (which is ridiculously expensive). If you have nuvi 2x5w, the only choice is to flash the Sg/My OS (which supports encrypted JCV).
Where in Thailand are you in? If it's not too far, I can probably help you to flash it.
You'll get: JCV, highway mode, lane assist, TTS (even on the 205w).