[356Guy]

It comes down to risk tolerance. Since there is no definitive cause/s the only prevention is some sort of replacement or upgrade program. Some people can sleep without having the upgrade done and others can't. I wish I were of the later type. I suppose many are oblivious to the issue which is even better. I'm trying to buy a car with the upgrade or at least one priced well enough that it makes sense to get it done. Its interesting to note that all the sellers I've communicated with so far don't believe the upgrade is necessary