I'm finally taking the plunge and replacing the stereo in my '02 RL w/NAV with an aftermarket unit (Sony). I'm wondering how the rear door speakers come into play with the OEM NAV/On-Star system. My NAV system was DOA when I bought the car and the manuals don't get into details as to how the speakers are used/muted when the NAV or On-Star "talks". In the '02 they have a separate output at the headunit which is why we lose them when replacing it.

Does the system mute the rear doors when it "talks"?

Does it use only the rear doors for guidance audio?

More curiosity than anything. If I lose the rear doors, no big deal.

 

I don't know about the OnStar thing, but in my case when I replaced the whole unit with a Pioneer the rear door speakers were no longer working! I ran an external amp for my speakers and sub, good luck.