stanpalg

Hi All,
Close to a year ago I got an awesome deal on an '07 TL with Navi, with 56k on the clock.
It's about that time that I started thinking about how to make the audio system sound better. I've read through countless posts and it seems to be universal knowledge that i'll be losing navigation prompts.
I was browsing the audio system connector Pinout, and it seems that there is a navigation channel on Connector A, pins 12 and 13. I was wondering if anyone knows whether:
1) this is the audio channel for the navigation system
2) if it is an audio channel, is it analog or digital?
3) if it is digital, is it standard PCM?

Here's the pinout, found in link 1 and 2:
http://www.tehnomagazin.com/images/A...%20harness.jpg
http://www.tehnomagazin.com/images/A...%20harness.jpg
http://www.tehnomagazin.com/images/A...pinout%202.jpg

I'm trying to think if there is a way to bring back navigation prompts. My thoughts are to use an aux input in a new stereo. The analog would be straight up plug and play, while a PCM digital would need some cheap DAC.
Thoughts?

stanpalg

Doh, can't edit.
Wanted to add that i'd like to add a non-navi double-din deck, in order to make it look as close to stock as possible.
Something like this: https://www1.crutchfield.com/p_113DP...?tp=5684&avf=Y