Hi there, I've got a 2017 Model S 75D with the cold weather package and live in the Greater Toronto Area. About two weeks ago, I was driving with the front windshield defog on Hi and the windshield heater on. Outside temp was -3 C and all of a sudden I had a crack in the windshield right across the lower driver's side where the defog hits the windshield. I assumed it was a stone chip, but couldn't find any impact. Contacted Tesla Service in Toronto and booked an appointment to take it in for inspection, which happens to be tomorrow. This past Tuesday, I had left the car at a GO parking lot outside for the day and while I was defogging the windshield to drive home, i,e, not moving, the passenger side cracked in a similar fashion. This was definitely not a stone chip! Outside temp was about -2C and same routine with the defogger. Anyone have a similar experience? I am ok to go through insurance if it is legitimately a stone chip but these seem to be a defect to me.