The back piece mat you are referring to, does not work when the one seat is folded down. We purposely designed our mats this way to give full coverage to the back of the car. No liquids or mud will seep between the seats. Our mats have coverage all the way to the back of the front seats. When both of the seats or one seat is up in the third row, you can fold the mat and keep it in the trunk/frunk of the car.I bought the trunk and frunk mats for our 7 seater as well and they fit like trash. I do not understand the idea of you cant use the mat when 3rd row are in used. I will post the review on Facebook groups to helps others avoid this company.
As for the sub trunk, our shipment was tampered with and those mats are missing. We had to order new sub trunk mats and will be sending those mats by air to our fulfillment center (not by sea). Once the mats arrive they will be sent automatically to each customer. Anyone that places an order with us for any of our products that are currently in stock should receive them within a few days.