I have a 2011 Jeep with a mini-plug aux input on the stereo. I plug my phone into this to play music, but to get normal volume I have to crank the volume up pretty high. It can get it loud, but then if I switch to FM or something later, it about blows me out of the car. I'm not sure if these phones are extra smart, but if they are really intended just for headphones, they are meant to drive low impedance at low voltage, and perhaps the car wants line level (high impedance). A long time ago I solved this with a little transformer from Radio Shack. Am I the only one who has this issue? I surfed all around for some sort of a transformer, converter, or adapter to fix the issue but I can't find anything.