I have a 2010 H3T, with Nav, Xm, Bluetooth, & Onstar. Before you try and upgrade to a 2010 head unit, you should know it does not support bluetooth stereo via phone, mp3 or any other device. The bluetooth system in the H3 is quite lame. It is connected to the head unit as a separate unit behind/underneath the head unit, but only works for phone calls through your speakers. I was quite dissapointed.

 

I'd do her!!

 

I heared you can install Costar Bluestar system, it is a module that replaces OnStar and let you use all the Onstar system but with bluetooth (disables onstar):
costartech.com - BlueSTAR

Hope it helps... (its quite expensive, over $250 i guess)

 

I have been using the GOgroove FlexSMART X2 ADVANCED Wireless In-Car Bluetooth FM Transmitter with Charging, Music Control and Hands-Free Calling , and it works great

 

How does that work, does it got thru the speakers or what? Looking at ways to do this mod!!

 

Fireman _343 ... Plug it in the Cigarette Lighter Socket and sync your phone with the device via Bluetooth, tune the FM radio to the suggested station frequency... now make and receive phone calls through your car speakers, or play music from your phone, If the music is playing and you get a call, it will slowly fade out to allow you to clearly connect to any phone call... Sound quality is Great and calls are very clear .