Questions about Hauck Sit on me Deluxe

If the middle seat has a headrest, then you can fit the seat protector. However, it will probably protrude onto the adjacent seats and cover the seat belt buckle. But you could at best fold the seat protector to the side. If a child seat is then mounted on it, it would also have to remain folded due to the weight.

Use the protection on all 3 seats in the 2nd row. You can still fasten your seat belt.