Maybe I should have been more specific posting that I have put the English only basic map (247 MB) on my four Garmin units. I have no Thai GPS units. What I have are Nuvis 750 and 855 and two hand held units, an Etrex and a GPSMAP 60. The basic map works great on all of them.

I use both my Nuvis to listen to Audible audio books while driving. Both units have 3.5 mm audio jacks. Garmin has gone backwards as far as I am concerned. None of the new units have this capability.