The hydrophobic effect of automotive glass can be achieved through various mature technologies, among which nanoscale coating and hydrophobic coating are the mainstream solutions. Nanoscale SiO₂ sol coating can form a micro-nano structure on the glass surface, increasing the water contact angle to a superhydrophobic state (similar to the lotus leaf effect). This technology has been applied to the side window glass of some original factory models such as the Toyota Camry. Its advantages are good wear resistance and unaffected light transmittance, but the cost of professional coating is high, ranging from 500 to 1500 Malaysian Ringgit, with effects lasting 6 to 12 months. For car owners who prefer DIY solutions, commercially available hydrophobic sprays (such as glass coating liquids) are an economical choice, priced between 30 to 150 Malaysian Ringgit. Spray application forms a temporary hydrophobic layer. Although the lifespan is shorter (approximately 1 to 3 months), it significantly improves visibility during rainy conditions, particularly for rearview mirrors and side windows. Note that the glass must be thoroughly cleaned before coating, and temperature difference-induced fogging should be prevented. In summary, hydrophobic technology has been maturely applied in the automotive sector, and selection should balance durability, cost, and application convenience.
