Android NFC BT Car Audio Setup

In the mood to try out the NFC capbilities of my newly acquired gadget I thought of doing something about my car audio setup (previously consisting of a stereo line connecting the aux port of the stereo to the headphone out of Nexus one using tasker to start music when connected).
Before I go into how I went about it, here is what it does now. When I keep the phone into my car’s phone holder, it automatically starts streaming music over BT from my car stereo and then when I keep it in my pocket, it stops.