8T0955453C, Wiper Bottle/reservoir, Audi, Audi A4 B8, S4

The primary benefit is keeping the windshield clean, allowing for a clear view of the road, which is essential for safety. 

Windshield washer fluid contains detergents that break down dirt and grime, preventing it from smearing across the glass. 

The fluid’s additives, like glycol, keep the wiper blades supple, which helps them perform better and prevents them from drying out or damaging the windshield. 

In colder climates, the fluid contains methanol or other alcohols to prevent it from freezing and damaging the system.