There is no way to design the back door of a truck to open and hang with a rope as flat as the bottom of the car. The purpose of raising the rear compartment of the flatbed truck is to ensure the safety of the vehicle during driving and ensure that the goods will not collide during transportation. The rear compartment of a flatbed truck cannot be made as flat as the bottom of the car. Illegal modification of vehicles will be fined and driver's license revoked.