I got in my 2006 audi A4 S-line yesterday at work. Started it up as normal and the stereo didn't come on, pressed the on button on the stereo and the stereo came to life but none of the display on the dash and none of the buttons on the steering wheel were working. I stopped at the services on the way home and turned the ignition off and the stereo stayed on, i had to turn it off by pressing the button again on the stereo. Spoke to my mechanic when i got in and he said it could be something to do with the coil behind the steering wheel and could potentailly be very exprensive to fix. Anyone else had this problem or an idea for a diagnosis and cost?? Cheers in advance for your help.