I asked my service dept about disabling the seatbelt chime, or at least delaying it until you put it in gear, but he said he contacted BMWNA about it and they said it can't be done because it's a safety feature. This strikes me as silly.
I personally buckle up each and every time, and would never consider doing otherwise. It's just bothersome to hear the chime the instant I start the car, which naturally happens one step before buckling up since the key is already in my hand when I get in. They really should give it a delay. Not as long as the passenger one, perhaps, but at least give a fella a chance to go through his preflight routine before it starts nagging.
Hang on, my MY07 Euro spec only does the chime when you drive above a certain speed (something silly, like 7 mph). But certainly not as soon as you turn on the ignition.
People who don't wear seat belts probably endured a lot of trauma as a child when there parents were forcing them to wear seat belts, getting strapped down like an animal with a big uncomfortable belt. Seat belts, the very symbol of chastity. That's why people don't like them. I've seen kids kick and scream and s**t themselves as parents tried to buckle em up.