I use one of these Hight-tech docking stations on the dash of my 1994 Jeep Wrangler. If for some reason it falls out of the "dock" or even out the door when I'm driving doorless, no worries. I have a nearly indestructible "dumb phone". I pipe the audio through the built-in phone speaker, avoiding the need for A2DP or even an AUX-in. No ground loops or interference from multiple bluetooth stacks.

Occasionally, I even hear a note or two over the road noise of a rusted-out 90's jeep built on 70's technology driven over unpaved roads. On the plus side, the roads are so terrible, I rarely drive more than 15mph, which keeps the noise minimal and the tunes-a-playin!

Follow up: I ended up buying this HTC-branded car charger (currently $3 via Amazon). It properly charges my Galaxy Nexus in "AC" mode, not "USB" mode, without my needing to resort to any sort of surgery on the device. Amazon reviews on these sort of gadgets are often quite difficult to sort the wheat from the chaff. I ultimately figured that if the charger was branded from a non-Apple phone vendor, it would be more likely to follow the "standard" high-power spec rather than Apple's "non-standard" spec.

I've been using that in my car for a year, and I am quite happy with it. Its reputation is well deserved, I believe.

I have voice calls feed into my car stereo system successfully (Alpine X100), and the Parrot voice recognition commands are surprisingly good. My main phone is a Windows Phone, but I've successfully used the Parrot unit with Android and several old Nokia Symbian-based phones.

The moment I can buy a Windows phone with sufficiently large storage (probably 32 will be acceptable, compared to the 16 I have now), I'll finally dismiss my constantly crashing iPod 100Gb, which I've been keeping in my glove box basically as as a HDD for MP3s, and get rid of that last part of Apple-world from my personal music playing experience. Using Zune / Microsoft Music only in my car has been virtually impossible so far, but the Parrot unit is even helping to do that, which I can't wait for.