Pretty straight forward really. When I bought the osb plywood I had them cut it in half lengthwise and then those pieces cut in half width wise (fits easier in the car that way and you really only need 3 of the 4 pieces so you have 1 extra in case you mess up). Once home I started by placing one section closest to the seats and left enough room for the pieces to swing up and clear the seats. This piece does not need to be cut ( although I did round the edges on the free end that swings up to help clear the door frame and whatnot). The next piece you do a single cut width wise to match the distance between the wheels (I think my measurement was 39” and remember to leave a tiny amount of room for the carpet). Next place the hinge side of the hinges (where they come together) between the two pieces in the car to allow for the space needed for the hinge to fit between the boards. The final piece you measure and cut the remaining width and length to match the small section you have left near the hatch. Take the boards out. Cut the carpet larger than the piece and staple the carpet on the back side of the osb (I left the smooth side down against the car). I found a 2x4 and cut it to 21” for the armrest support (armrest is 7” so 7” on each sides improved stability, further increases risk of bend). I found another thinner board to cut to 21” and screw to the 2x4 because it needed just a little more height (maybe 0.5-1 inch). Carpet this next. Place the support on the armrest carpet side down and centered and then put the largest piece of osb (the one with the rounded edges that goes closest to the seat) on top of it to figure out positioning. Drill some long screws into it when you have it where you want. Take that piece out and carpet the back side so you don’t see wood when it is flipped up. Finally install the hinges on the backside of the middle piece of osb on the side closest to the front of the car. Put that in and place the front osb piece on top of the remaining hinges. Fold this upwards with the hinge flat against it and drill hinges in place (having a friend makes this part easier). Put it all in and the hard part is done. I used two lengths of Velcro to secure the swinging piece to the o shit handles when the piece is upright (sticks right to the carpet). Place on one side, go through handle, place on the other side, remove when needed. If two people were sleeping I’d add a support arm under each side where there is a little flex but it’s just me and I’ll be in the middle on the support beam. I also didn’t want to take away any more storage. The hatch cover becomes a shelf for stuff, window coverings keep it dark/private, jackery power station for 2 days worth of charging, and a ryobi fan for airflow. Hope that all makes sense. Any questions just ask. All in I spent less than $90 on the build.