I have an 06 Z4 M Coupe. My Samsung Galaxy S3 phone is incredibly flaky with the Z4's aux input. I've determined that the only way to get things to work is to set the car radio to aux, plug the audio cable into the phone first, start the audio on the phone, then plug into the aux jack last. Any other order just plays audio through the phone itself. It's as if the phone doesn't notice it has a jack plugged in. And once it's working, the audio switches back to the phone whenever a song/podcast stops. At that point, I can usually get it to switch back to aux playback by unplugging the aux jack (car end) and plugging it back in again, though the static pops are nasty. With any headphone, or with my other cars (Mini & Subaru), the phone works perfectly normally: you plug in the jack to the phone, the phone audio cuts out and you get audio on the aux. Order doesn't matter. Also, when I use my old iPhone 3GS with the Z4 I have no problems. I've already replaced the Z4's aux jack which didn't change anything. I also found I had a bad aux cable which added to the confusion, but have now eliminated that from the equation. Also, this is all done with phones that are running on battery only which presumably eliminates the "floating ground" issue that may or may not be present in my car. So any ideas? I've read that there may be issues with the aux jack on the Samsung being "euro" size which may lead to issues, but I've tried many different cables with no difference. In any case, the fact that I have to plug in the car end of the cable last seems to suggest an electrical problem, not mechanical. Any ideas? If it comes down to a decision between the car and the phone, well, good bye Samsung.