1992 BMW 525I User Comment / Complaint

I am wondering how the manufacture determines which vehicles are affected by a particuliar recall. a couple of examples, i have a 1992 bmw 525i and have experienced two failures related to recalls one concerned the ring in the steering column related to the airbag broke and had to be replaced and the other had to do with the cooling system where the termostat stuck and the pressure cracked the radiator. these failure occurred a few years back and i would ned to check my maintenance records to get the exact dates.