
If anyone has ever wondered about the rear seat material in the C-HR, they're made of Piocelan polyethylene/polypropylene (PE/PP) hybrid foam and there's a wire frame inserted into it for greater strength. Also the foam will absorb impact in case of an accident so your passengers won't sink into the seats.
Here's a better explanation of the seat foam: https://www.plasticstoday.com/automotive-and-mobility/polyolefin-foam-forms-rear-seat-base-toyota-c-hr/107042175547359