Fit: Some mud flaps advertised as “BYD” may be generic or for older models; check that they specifically say Atto 3 (2022‑2025) or Sealion 6 / Seal U.
Material: ABS plastic or rubber / composite – ABS is stiffer, more durable, but might crack; rubber/composite is more flexible.
Install method: Some require drilling, others use clips or existing wheel well holes. If you don’t want drilling, pay attention to that.
Coverage: How far the flap extends behind the wheel matters (for stone splash, mud etc). Also whether they cover front & rear.
Quality: Some off‑brand ones may be less durable, or look “cheap”.