I picked up my Model S from the factory last Tuesday. 5 days and 344 miles later, I noticed a 6-inch hairline crack in the rear windshield, surrounded by a handful of "star" cracks. There's no damage to the rest of the glass or paintwork on the car. Has anyone seen this before? I don't know what to make of it. The car was already booked in for service at the local SC next week due to whistle noise coming from the front windshield at freeway speeds, so I'll be asking them about this as well. I contacted them to ask if it's safe to drive, no response yet. Is it possible that this was caused by a production defect, or is it more likely that I just got unlucky and the car was hit by rock chips or some other object?