On a 00MY 9.5, I have a few questions:

1) is the mute for the radio active when grounded? Can it be grounded
safely?

2) Assuming that this is so, it looks like the radio will probably
switch audio streams when the mute is active, probably turning off the
radio's audio channel and directing the cell phone's audio to the
speaker system.

3) I'm going to use this for an amateur band HT, which does not have a
squelch out, so I will probably just wire it to a button, no big deal
here, although I could put in a small delay circuit that samples the
audio from the speaker. That would work.... I could make it
auto/manual for the HT....

4) while poking around in the innards of the dash, I noticed a small
coax type wire. I assume that it's probably the Onstar connection
(which I do not have). Any guesses if this is just a wire up through
the headliner to a location where the antenna might have been? Just
curious here, no particular use for it.

Harvey