Thanks for the link.
I going to have a look at it.

I tried and now Igo is using the phone speaker and the Ford app stays connected.
But I do not know exactly how I solved it.
I tried al 7 BT channels conform the link above, but none worked.
Then I noticed that the line in my sys.txt was: navigation_audio_stream = 4. I changed this in navigation_audio_stream=4 without spaces,
but at the same time I cleaned my cache memory for the Igo app on my phone.

Now it is working and Igo is through my phone speaker.

But the toggle switch in the Pongo skin is not working. It shoult force the phone speaker. In other programs like Flitmeister you have the same option to force the phone speaker and that works well.