Where do the majority of passenger compartment water leaks occur?

The majority of passenger compartment water leaks are typically found at glass to metal joints. These areas involve the seals that are used to fasten windows and windshields to the car's body. Over time, these seals can degrade due to environmental exposure, improper installation, or damage from impacts, leading to potential leaks.

Glass to metal joints are critical points in the vehicle's structure because they are subjected to various stresses, including vibrations, temperature fluctuations, and even physical impacts. If the seals around a windshield or window become compromised, it can allow water to seep into the passenger compartment, resulting in issues such as mold growth, electrical problems, and interior damage.

Understanding this helps technicians focus on inspecting the integrity of these joints during routine checks and repairs, ensuring a more robust and leak-free passenger compartment. While door seals and sunroof drains are also common points of potential leaks, the prevalence and significance of glass to metal joint failures make them a primary concern in automotive water leak diagnostics. Floor mats, while related to moisture accumulation, are not direct sources of leaks.