Fantastic tutorials. I have this working with TTS on my Motorola Android 8 mobile phone flawlessly with VocalizerEX2 and English AUS voices.

Unfortunately I cannot get it to work correctly on my Android Head unit in the car. It is running Android 10. iGo version - iGO (Israel) NextGen 9.18.27.687519.
On both devices I have setup the folders as per Hardcoreita's instructions. I have had to delete the files in the Phoneme folder. It appears to work partially when selected in Regional settings but once the unit is power off and back on it no longer works.

The Language settings Text to Speech Output is selected to the correct language in VocalizerEx2 engine.

Any ideas? Or is this setup not compatible with the latest Android version. Worth noting that none of the original TTS voices and Vocalizer 1 work any more.