Two problems related to warning light on have been reported for the 2007 BMW 3 Series. The most recently reported issues are listed below.
Passenger air bag warning light and seat beat warning light randomly turns on but it happens most frequently when someone is sitting in the passenger seat.
After cleaning my car I tried to start it, when suddenly a warning light popped up indicating that there was a passenger restraint malfunction. The warning, further indicated that all seat belt be worn immediately when driving. I took it to the BMW dealership only to find out after paying for diagnosis fee, that there was an internal fault in the rollover protection controller thereby affecting the deployment of airbags in case of a crash. The dealership told me this safety feature for convertibles wasn't under dealership warranty. This a safety issue and should be addressed as such, I would think.