Came across a complaint at Amazon.com about the double Amaray hub causing a TPM feature disc to crack and then took a look at mine. And to my shock, I found a scratch on the upper side of the disc around the centre. It doesn't look like a crack. Only a scratch. But the question is, what caused the scratch? Could it be stress on the disc from the plastic hub? I am of course speaking not about the standard Amaray hub but the one of the added disc holder.