[dishe]

No problem, delete those reg keys and let me know what you think.

I'm sort of an A2DP enthusiast, I guess... I've been meaning to write all this stuff up as a full tutorial/article, but I haven't had time- a lot of people don't know the ins-and-outs of bluetooth stereo.

Anyway, forgot to mention, you CAN initiate the session without taking the phone out of your pocket, but A2DP will not start automatically when you enter the car. That is ON PURPOSE since when connected, it will route all audio to the car speakers, including system alarms and alerts which you might not want (imagine it trying to alert you of an important reminder while the stereo is set to FM tuner- you'd never hear it!).
However, set the stereo to BT Audio (assuming the menu is similar to the Xplod 2500, which I've used and currently own two of), and press the play/pause button (which is printed in small letters over the 6th radio preset button on mine). One press initiates a paired connection with the last device used. Assuming no one else has used your stereo with their phone, it will autoconnect to your TP.
A second press will hit the play button on any open media player. This is good to know in general, because you should always press that button to pause playback right before you turn off the car. Otherwise, as soon as the phone realizes its not connected, music will come blasting out of your pocket!

IF these things were programmable/hackable, I'd set it to automatically send that pause command upon turning off the car, but alas...