1) Passenger restraint system malfunction. According to information on the web and several BMW forums, this is a common problem on these vehicles and it is a serious and inherently unsafe issue that should necessitate a recall from the manufacturer. The root cause is typically a malfunction of the passenger seat pad that is utilized by the passenger restraint system. BMW service repair cost is $2,700-$3,000. This is really outrageous given that it’s part of the safety restraint system and many BMW 5 series (and likely others) have this problem.