I hooked up the line out from the mount on my 510 to my car stereo line-in (I use that same jack sometimes for my iPod so I know it works). While I clearly hear the lady's voice giving me directions from the TomTom, it doesn't seem to pass my bluetoothed phone connection through the line out. It always plays the phone conversation through the TomTom speaker. Is there something I am missing that is preventing me from effectively having this work? Thanks!