Those alarms drive me crazy for some reason. I've been wearing seat belts before they were installed in cars! And I know when the door is open so why tell me.
Maybe the door open alarm is good for people who forget their keys, but as much as I care for my 2003 E-320 I ALWAYS lock the doors, and that's impossible without the key in my hand.
So I'd like to shut those damned thing up.