The cracks in the windshield from the caretans on the Ford Focus 2

There may be two reasons for fractures in the windshield area of the windshield.

1. Temperature difference: hot air to glass in winter or air-conditioned cold air in summer. Glass can crash with a loud clap.

2. To strike a "caretor" or a stroke of a porter when he is replaced. The impact may result in a micro-fracture, which will start to increase, especially at large temperature differences inside and outside the vehicle.