Hi

Very simple question, might be simple but since I drive a bmw for only a few months...
It happened at least twice (probably more but the music covered it

)... while driving, I hear a small DING (electronic) like a tone sound... does that mean something?
The inspection lights are OK (all green)... no check engine, door left open, trunk open, no ASC disabled or ABS problem,.... !!
Any idea?
Thanks