[David Mays]

Hi. I'm the guy who wrote the BTAudio program mentioned in this thread.

First, I'm glad to hear someone was able to make use of it, and thanks very much for purchasing a registered copy!

Robb, you are correct that my program only activates a mono audio stream. This is because it is making use of the hands free profile (HFP) which is what your car's entertainment system is no doubt using to communicate with the phone.

As suggested before, A2DP is the only way to get reasonable audio quality over BT, but if the BT peer device (in this case your car) does not support that, you are stuck with the low quality (~8khz I believe) monaural sound supported by HFP.

It's also an unfortunate reality that many Windows Mobile devices lack sufficient processor power to provide a good A2DP stream without stuttering. Some devices reach upwards of 30% processor utilization during A2DP streaming.

So, while the convenience of BT is nice, you would be much better served by a solution that uses a hard-wire connection for the audio coming out of your device, if you want decent sound quality.

A final consideration is that of battery life. A2DP streaming uses by some accounts, an order of magnitude more energy than HFP audio. That is, even if you can find a very good A2DP solution, more than likely you will still need to plug the phone into the car for power, or else run the battery down rather quickly.

If you have experimented with any of the other suggested A2DP solutions though, I'd be interested to hear about them.