This is true, but the key difference is that people aren't mucking about with the latest installation of their airbag, and criminals aren't gaining access to peoples' cars without their knowledge and tampering with the airbag; in other words, if the airbag fails it's very likely the manufacturer's fault, they exercise almost total control over the system in the vast majority of cars.
Contrast this to computer security problems, which are sometimes the fault of the security provider (in this case Microsoft) but just as often (if not more often) is the result of user interference (people misunderstanding how the security system works or disabling security altogether) and malicious intent.
The real culprit isn't Microsoft, but the people who write malware; for some reason we don't spend much time blaming the criminal and we heap all our discontent on Microsoft. Maybe because they're the easy target here. At any rate, hopefully this shows why a lawsuit against Microsoft is illogical; they do not have sufficient control over the situation to prosecute them.