When buying and selling a second-hand car, how to tell whether the leather seats are original or aftermarket?

Look at the details and workmanship: the original leather covering is neatly routed, the stitches are evenly spaced, the corners fit seamlessly, and it fits perfectly with the seat foam, with no bulging or looseness. Backpack leather is prone to problems such as skewed wiring, warped corners, and inconsistent fillers.
Look at the texture and color matching: the original leather texture and color are exactly the same as the covering of the door panels, center armrest and other locations. The leather of the back bag is prone to color difference and the texture matching is poor.
Check the wear consistency: The wear degree of the original leather will be consistent with the vehicle mileage and age. If the vehicle has high mileage but the seat leather is brand new, it is most likely to be refurbished and covered later.