Jetset

Nav to Non Nav completed in Australia.
I did have a lot of connectivity issues with the A/C Auto Amp to the M66 plug.
As it turned out, some of the female pins of the M66 plug were too loose for the male pins of the A/C Auto Amp. Something I dismissed as the car was built in September 2018 and had never been opened up.
I had to remove the female pins, [6] [7] [10] [11] [26] [27], from the M66 harness and push a small precision flat blade screwdriver in the back of those female pins, getting under the spring.
It closed them up and now there is a solid electrical connection.
With all the troubleshooting, I have a spare Non Nav A/C Auto Amp - 27760 1EA0A plus an extra four female pins to place into positions [6] [7] [26] [27], factory crimped. These are the pins specifically for this harness, not the M67 pins.
Pm me if anyone is interested.

A HUGE thanks to 2SIC4U for all this info to make this conversion. It would not have happened with out this post and video.