Ok so I will answer my own question to help + it is not posted in the tech area. You need a Metra adapater harness (MZTO-01) for radio install that includes an access port. This access port will allow you change clock to appropriate times with the factory radio when needed. You will loose your MPG current ,MPG total, and Miles remaining info from the center dash. The harness also retains use of a/c function from what Gene @ metra says. It looks like the above post has no A/C function data.
I believe the best way around this is to get a scanguage or other OBD2 type data guage if it is important to you, however some receivers have some driving info integrated into them now. Hope this helps anybody else.