The windshield appeared to have spontaneously cracked overnight while parked on the driveway. The crack formed across the top of the windshield, across the eyesight. The day before, the car was at the dealership for an oil change and tire rotation. Unknown if lifting the car for the tire rotation caused the stress that may have caused the crack formation. The car was taken back to the dealer and the windshield had to be replaced. A claim to our insurance was done because the dealer said this was not covered by the warranty. I did not see any chip in the windshield that would have caused this.