I tried several voices (naturals and tts) even in different langages, the first word of the sentence is cut. I tried two diferent engines also. I think the audio systeme of the car needs a short time to play the sound and therefore the first word is not heard. I tried to change the audio stream with the settings you gave me but the problem remains.

I think the best would be to edit the tts voices files to add an extra word for instance instead of "in 100 meters..." to add an "and" so it would say "And in 100m..." Therefore if the first part is cut I woukd hear "In 100m..."

Can someone tell me which file to modify and how ?

Thanks