BYD Cabin Air Filter Se8121211 for S7 (specific trims, 2016–2020) restores crisp airflow and reliable defogging using high-surface-area pleats engineered for strong dust-holding capacity at low resistance. A warp-resistant frame and precise seals prevent bypass leaks, protecting ducts and the evaporator from debris buildup. Activated-carbon variants help neutralize traffic odors and VOCs for more comfortable commutes. With OE-accurate dimensions and orientation markings, the DIY swap behind the glovebox is straightforward and repeatable. Replace every 12 months or 15–20k km based on climate and usage to keep HVAC components healthy, reduce cabin haze, and deliver consistently cleaner, quieter interiors for your S7.