Artōrius Tommi

After playing around in the hidden engineering menu my media interface option disappeared. Now, when I connect my iPhone or iPod nothing happens. The AUX input no longer works either; however, I can at least select AUX from the drop down menu under the Audio tab. I've taken my car to the dealer here in Germany, but it was a huge waste of money and time because they didn't know how to fix it. The car is US Spec. Does anyone have any advice?