I have some cargo nets with no place to hook them on my Model Y so I made some that simply are placed under the trunk shelf. When not in use, they fold down to be out of the way.

September 3, 2020 - Added a new revision that tightens up the fit and adds a hole to secure clip to the bottom of the platform if you want to make the install a little more permanent. I originally printed this with PLA and although the hing is strong, the heat in the car caused the part to warp a little. Funny enough though the hing part never broke. I'm now reprinting the revised version with PETG to handle the heat better and will add even more strength to the part overall.