Does anyone know if there is any overtemp circuitry built into the Nav system and/or the HK audio system on 330i? Last night on the way home from work I turned on my stereo (HK Audio w/Nav/trunk mounted CD changer, all stock) and got only silence. THe power light came on indicating that the audio was turned on, I turned the volume up still no sound. I switched to the tuner and turned the sound up again -- nothing. Switched back to CD and changed to a different CD, switched tracks and turned the sound up again and nothing. I turned the system off and on again, repeated the entire process and still no sound. I tried turning off the HK button, it made no difference. I started playing with the settings on the "System settings" screen and when I adjusted the "Nav volume" setting, the radio turned on very loud (scared the cr*p out of me) and from that point on has played normally. The indicated temperature on the dashboard readout was 99 degrees F and the car had been parked in the sun all day. I don't think I'd get anywhere with the dealer at this point because it's working now. Anyone have _any_ ideas?