I'm looking to buy a roadster with its first PEM. My guess is that the PEM will fail shortly. My question is the following. After PEM repair, is it known to fail again? In other words, was it just the first iteration of the PEM that needed fixing, or is it some kind of routine repair that is going to come every few years? And is it possible that there is a shortage of PEM eventually? What will happen after that? Thanks!