My car has bluetooth support for handsfree calling, but no A2DP. I tried a few other solutions, then hit upon the TuneLink Auto (which comes in iPhone or Android flavors) - http://newpotatotech.com/TUNELINK_AUTO/tunelink_auto.html

It sits in the lighter plug and makes an A2DP connection with the phone, and then outputs the sound (in stereo) out a 3.5mm headphone jack. Additional plusses are the USB port I can use for charging the phone, and the fact that it's also got an FM modulator, so if I'm in a rental car, I can bring it with me and have it work over the crappy FM.

In my car, the aux in is actually in the center console, a couple of inches from a lighter plug, so the thing sits in there unseen and just works its magic. It really is like magic, too. I get in the car and turn it on, and the thing takes just a couple of seconds to reconnect to my phone and tell it to start playing. If I get a call, the phone knows to pause the music and switch over to the handsfree connection directly to the car.

There's an app you can use to configure it, like to set the FM frequency and stuff, but I never use it. The one goofy thing is that they sell a separate Android and iPhone version, but I can't imagine that either version wouldn't work with any old A2DP connection from any device. So, why the 2 packages? Who knows...

Anyway, if you had the lighter plug and aux-in ports in convenient spots, this might be a good solution for any of you in the same boat.