I plan to use my GX for some camping this summer, so I wanted to design the lowest-profile sleeping platform that I could build that will come out of the truck easily for storage. I figured I would share some pictures and dimensions to help out someone else trying in the future. These dimensions are pretty good, but not perfect, there is about 1/2in wiggle room between the wheel wells, and some open space behind the wheel wells so the hinged section can fold forward. I realized the dimensions sheet switches from fractional to decimal dimensions, but you get what you pay for.
It would be a lot easier to just make the whole platform a consistent width, but I wanted to get as much support for a mattress as possible since my fiancee and I will both be sleeping in it for a few nights. After I cut the shape for the rear-most section I layered the middle section on top and used a router with a template bit to copy the shape, rinse and repeat for the section at the front. I am also a little over 6' tall so this is about as long as I could make the platform. I used locking hinges like these for the "legs" Amazon.com - https://a.co/d/8NhBGMj, and the middle section overlaps the legs by about an inch when it is extended and feels reasonably sturdy. I used 1 sheet of junky 3/4in plywood that was underlayment in a previous life, and it is covered in a $15 outdoor rug from Menards. The whole assembly stores behind the 2nd row without any issues, and with the mattress on top it is pretty quiet/doesn't bounce around too much on fire roads. The sections are all hinged together so I can drive to a campsite with the forward-most section folded under, park, scoot the seats forward, then deploy the last section and I was limited by vertical clearance (hence the corner cutouts).
The shaded sections indicate material was removed:
It would be a lot easier to just make the whole platform a consistent width, but I wanted to get as much support for a mattress as possible since my fiancee and I will both be sleeping in it for a few nights. After I cut the shape for the rear-most section I layered the middle section on top and used a router with a template bit to copy the shape, rinse and repeat for the section at the front. I am also a little over 6' tall so this is about as long as I could make the platform. I used locking hinges like these for the "legs" Amazon.com - https://a.co/d/8NhBGMj, and the middle section overlaps the legs by about an inch when it is extended and feels reasonably sturdy. I used 1 sheet of junky 3/4in plywood that was underlayment in a previous life, and it is covered in a $15 outdoor rug from Menards. The whole assembly stores behind the 2nd row without any issues, and with the mattress on top it is pretty quiet/doesn't bounce around too much on fire roads. The sections are all hinged together so I can drive to a campsite with the forward-most section folded under, park, scoot the seats forward, then deploy the last section and I was limited by vertical clearance (hence the corner cutouts).
The shaded sections indicate material was removed: