So its only -2C here which is not very cold for March in Northern Ontario. Our M3LR started preconditioning on schedule for 730am depart. When my wife got into the nice and toasty warm car she observed that the rear window was cracked from around the rear defrost lines down to the bottom of the window and then across most the width of the back window. Car is 6 months old. Absolutely no ice on the window, to impact to the window or anything like that. I've put in the service request but wonder if anybody has had luck with Tesla covering the replacement? This is not an impact issue clearly when the rear defrost kicks on it ended up cracking the window. Anybody with similar experience?