I have had great success using my Android Nexus S 2.3.6 with my new 2012 VW GLI Autobahn with RCD-510 stereo, which has bluetooth integration for A2DP audio thru the stereo and phone, as well as the built in speakerphone of course. I'm very happy with how well it's worked except for one problem.
The display of the phonebook via the car's MFD (multifunction display, between the speed and tach gauges), shows all my contacts EXCEPT those on my favorites, like my wife, best friend, mom, brother, i.e., the people I call most often. I can usually find them thru recent calls, but it seems silly that those don't show up in the phonebook when people I haven't talked with for years show up by virtue of not being favorites.
Anything I can do to help the phone show the favorites to the car as part of the phonebook? I have done phonebook update a couple times, but no luck so far.