BYD's headrest has a groove with a buckle that can be pulled down.
Proportional tilt of the rear seat means that the backrest of the rear seat can be tilted proportionally. Relative to the overall tilt of the rear seats, the flexibility of proportional tilt is higher. Only half of the backrest can be laid down to place large items, and the part that is not laid down can still be seated. Then when you need to take big things out, such as fishing, camping, mountain climbing and other activities. You can put down the back seat, so that you can put a lot of things to take when you travel in the saved space. But the disadvantage is that when the back seat is put down, people can't sit in the back seat, and the number of people in the car will decrease. This is a disadvantage. After all, there is room and people can't sit too many things.