Since updating my iPhone 3GS to iOS 4.2.1 about a week ago I've been having some issues with with voice control over bluetooth in my car. Back when I was on iOS 3.1.2 voice controls didn't work over my car's bluetooth, which meant I had to speak up a little to talk into the iPhone's microphone on my dash, but bluetooth still worked for calls so I was fine with that. Now with iOS 4.2.1, the phone attempts to switch to my car's bluetooth microphone when I activate voice controls, which would be great, expect that there seems to be a serious conflict when I'm playing music through my car adaptor. Basically, the bluetooth and the car adapter seem to duke it out and switch back and forth every couple of seconds when I activate voice controls, and voice commands don't work. Anyway, I'm wondering if anyone knows of any jailbreak app solution that would disable voice control over my car's bluetooth and return things to how they were in iOS 3.x when only the phone calls themselves went through my car's bluetooth.