Which factor is critical for ensuring the durability of the windshield installation?

Proper cleaning and preparation are essential for ensuring the durability of windshield installations. This process typically involves thoroughly cleaning the bonding surfaces of both the glass and the vehicle frame to remove any dirt, dust, grease, or old adhesive residues. If these surfaces are not meticulously cleaned, contaminants can prevent the adhesive from properly bonding, which may lead to leaks, moisture intrusion, and eventual failure of the install.

When the surfaces are prepared correctly, the adhesive can form a strong bond that allows the windshield to perform effectively, providing structural support to the vehicle and maintaining safety in case of a collision. This is crucial, especially in modern vehicles where windshields contribute to the vehicle's overall structural integrity.

The other options, such as weather conditions, glass thickness, and technician experience, play roles in the installation process but do not directly address the immediate need for a clean and prepared surface, which is foundational for a successful and durable installation. Weather conditions can affect curing times, glass thickness may impact impact resistance, and technician experience can influence the installation technique, but without proper cleaning and preparation, these factors cannot yield an optimal installation.