I have a n HTC EVO and a really nice car stereo system. I have a 3.5mm headphone jack coming from my stereo that I use to plug in MP3 devices, phones, etc. The problem I am facing with the EVO is that it seems to think that when the headphone jack is plugged in the microphone on the EVO shouldn't work. I would imagine this is because most of the time when you plug in a headphone jack it expects th what ever is on the other end to have a microphone. In this case, there isn't. I would like to be able to talk on the phone in my car while hearing through my car stereo speakers. Everything works great except whoever is on the other end of the line can't hear me cause when the headphone is plugged in it doesn't use the EVO's microphone. Does any one know how to override or fix this behavior?