Passenger side seat belt (when no passenger) flaps when the top is down. Any cures?
Not unique to your Buick. You can try fastening it.
Thanks.
Never had the problem with my Sebring or Toyota convertibles.
As @Purebred said, fasten it.
Then the belt will be snug from the spring that retracts it.
This should keep it from bothering you.
Yosemite