Audio Systems: In dash navigation system, fm modulator, chevy impala

Question
I have a 2003 Chevy Impala that I am looking to install an in dash navigation system. The system I am looking for has an am/fm receiver, GPS and Cd/DVD player. My question is will the message center alerts still be accessed through the new system.  For example, if my tire pressure is low, I get a message. When I correct the problem, I use the stereo to reset/clear the message. My current stereo also is where my car alarm is set. How do the things work if a different stereo system is installed?

Answer
Functions that are incorporated into the factory headunit will not work if you put an after market headunit in the vehicle.
That said, you might talk to the folks at http://www.crutchfield.com about what your options are. You may be able to interface through the CD changer input for the factory system or through an FM modulator but they would be the people to discuss things with when you want to interface to an existing factory system.

JM