Please try this... close all windows and turn off radio/music in the car and remain seated behind the wheel. (in a peaceful area). After the ignition is switched off, there comes a sound behind the steering wheel (buzzing) similar to that like an antenna going down from the outside. WHAT is this sound ? and where doea it come from ? ANYONE please??? coz i now know that it happens with 2 of my friends with their 740s and we all donno what it is...