I would agree with this. I rarely see cracks on tails that have never been removed. I put my first set of jspecs on shortly after buying my Z and they lasted about four years before starting to crack, and once they started the cracks spread like crazy. I am fairly sure that my installation wasn't as even as it could have been and caused them to crack prematurely when compared to the usdm units that had been in the car its entire life.