Actually (technically) the non-iDrive display doesn't turn off. It just changes mode to display the clock. BT, gongs and bongs and BMW assist all still function with the "display off".
Originally Posted by jwac
Probably because it's all an integrated module, and iDrive uses the audio system's amplifiers and speakers for BMW Assist, BT and its bongs and gongs. I imagine the non-iDrive audio system is never actually "off" either when you hit the "power" button, even though the display turns off.
2011 328i Convertible
: Mineral White; Oyster/Black Dakota Leather; Premium, Sport, Value; Sport Wheel w/paddles; Heated Front Seats; Satellite radio; HK Sound
2012 528i Sedan
: Titanium Silver; Oyster/Black Dakota Leather; Anthracite Wood; Comfort Access; Side & Top View Cameras; Cold Weather, Premium; Technology;
: Titanium Silver; Gray Leather; Premium, Sport; Fold Down Rear Seats; Xenon Headlights; Navigation System; HK Sound
2001 X5, 2009 528i