Since Froyo, it seems that whenever my phone is in the car dock, the audio volume coming out of the 3.5mm audio jack is always at maximum. That makes sense as a general concept, since you're typically controlling volume in the car with your car stereo's volume knob. I use a cassette tape adapter, though, and it can't handle high-powered signals; the sound gets distorted if it's over about 75%.

I'd love to be able to turn the volume down, but the car dock buttons don't seem to do anything when there's something plugged into the 3.5mm jack. I even tried using Audio Manager Pro ([App Of The Week] Audio Manager Pro - Android Police), but even turning the media volume slider all the way down doesn't change the output volume.

Any ideas?