Damage not associated with any type of object or impact is usually classified as a stress crack. A stress crack can be defined as a break that results from excessive pressures applied to the windshield by torsional flexing. This stress can occur during the process of leveling your coach, especially in extreme conditions. Driving on excessively uneven ground can cause twisting of the front cap on some coaches. If your coach has ever sustained a significant collision, especially in the front cap area, a distortion of the windshield opening may have occurred. In this case, we suggest having a qualified body shop inspect the opening prior to replacing the windshield(s). Click here for more detailed information.