Ultimate Road Trip Car Conversion (Honda Fit)

When my wife and I found out that we had two months to take the cross-country road trip of our dreams, I immediately knew that I was going to transform my ordinary Honda Fit into the ultimate road-tripping machine. One of my keys to a great road trip is flexibility, so I wanted the flexibility to sleep in the car in parking lots, rest stops, or the wilderness. I knew this would come in handy after a late night drive, when its raining and I don't want to set up a tent, or other unforeseen circumstances.

I had slept in my Fit before, but I knew that with two people and all of our gear; I would need to build an integrated storage/sleeping unit. The idea was simple, build a platform to sleep on with enough room for all of the things we need underneath. The Honda Fit combines great gas mileage (39 mpg) and unexpected roominess making it a great car for my wife and I on our road trip. However, the principles in this Instructable could be applied to any hatchback, SUV, or van.

What you’ll need:

Road-trip worthy vehicle, plywood (3/4 and ½ inch, 1 sheet of each 4x8 ft), 2 inch wood screws, wood glue, hot glue gun, large sheet of cardboard, box cutter, 7-8 ft of continuous hinges (piano hinges), jig saw, drill, mosquito type netting, old sheet, and magnets.

(optional: table saw, miter saw, orbital sander)

Those are 72" Thermarests in the photo. Also, the weight of all the wood is less than the weight of the seats I removed!

Before you start anything, you need to look at your car and decide how things would best fit. For my Honda Fit, I decided that I would use the height of the wheel wells in the rear as the level of our sleeping platform. The Honda Fit also has seats that fold flat in the back which I was able to remove to create some large space for storage. I also pushed the two front seats all the way forward and measured the length of the cabin at the proposed platform level. It measured just over 6 feet, which is exactly my height. With these details in mind, I began building the frame of our sleeping platform.

First, I built a T-shaped spine that divided the cabin in two with the top of the T being at the platform level. I used 2 inch screws and wood glue to secure the T shape. For my frame I used ¾” plywood, because I knew it would be sturdy, and I had it on hand. My spine member rested along the floor near the rear of the cabin and had a foot extending down to the floor of the removed seat wells. The top of the T spanned from the rear of the cabin to as far forward in between the front seats as possible without making driving uncomfortable. For me this meant being able to shift into 4th gear without my elbow hitting the spine.

To support the spine, I made two ¾ ” plywood cross members. For ease of removing the platform to access the spare tire and for storage after our trip, I didn’t want to screw or glue the cross members to the spine. Instead, I made ¾” slots in the bottom of the spine and the top of the cross members, so that they slide together at a 90 degree angle. I also cut notches in the cross members so that the top of the cross member would be level with the top of the T-spine. I chose the location of the cross members based on how I wanted to split the storage space in the rear of the cabin. The width of the cross members was determined by the width of the cabin at those points. I added notches in the cross members and two cross bars to give the whole frame some rigidity. Then I moved my attention to the platform.

Addition: I ended up cutting large chunks out of the long "T-spine" to save on weight. 3/4" Plywood is very strong, so I didn't need that much material.

I wanted the sleeping platform to follow the contours of the cabin walls, so I started by prototyping the platform with cardboard. I put the seats in their full forward position and cut out two six feet long pieces of cardboard. I placed them over my frame and used a box cutter to rough out the cabin profile. For my platform, I used ½” plywood in order to minimize weight while retaining strength. Using my cardboard patterns, I traced the platform shapes onto the plywood and used a jigsaw to cut them out. I then placed them in the car to ensure the correct fit.

Obviously, you can’t drive with the seats pushed all the way to the front of the car, so the platform needs to fold back into the cabin. Using the cardboard, I found the location that I could fold the plywood back without hitting the sidewall or the ceiling. For me, this was about 1/3 back from the front of the platform. I drew a line where I wanted the hinge, and I cut the plywood with a jigsaw. Using the continuous hinges is easy. Line up the two pieces together, center the hinge over the two pieces, and screw in the screws that come with the hinges. I also used these hinges to create a hatch to access the storage space between the cross members. I drew out the shape I wanted for my hatch making sure that there would be support underneath for the hatch (enclosed as well as for the remaining platform). At the hinge of the hatch, I cut the platform across entirely, so that the front could also hinge upward. In my Honda Fit, this would allow me to easily fit and remove a large storage bin underneath the platform. I used a jigsaw to cut out the hatch and an oblong hole to use as a handle. After sanding all the edges, I laid the pieces all together, and screwed in the continuous hinge in the two places shown in the picture. This all resulted in my platform being divided into three foldable sections connected by the hinges. I laid the platform on top of the frame and made sure that all of the hinges worked properly and the wood was properly cut.

The last thing that the platform needed to be structurally sound, were supports directly behind the seats in the front part of the platform. For these, I simply measured the height from the floor of the vehicle to the bottom of the platform right behind the front hinge and right behind the seat. Then using ½” plywood, I cut out a U-shaped support with the legs being those lengths. I put them in their place and checked to make sure the platform was level and adequately supported throughout the cabin.

To keep the platform and frame from sliding around in transit (and scuffing the cabin walls), I used small pieces of ¾” plywood, set the platform in the location I wanted, and hot glued the small pieces to the underside of the platform surrounding the frame supports. For the U-shaped supports, I used longer pieces of the ¾” plywood. These keep the platform from sliding relative to the frame and keep the U-shaped supports in the correct location.

I'll add pictures of these tabs at a later date to make it more clear.

To offer airflow while sleeping in the vehicle, I wanted to be able to keep the windows down without letting bugs in. So, I got some netting from an old tent and sewed window sleeves. With the car door open, I folded a large piece of netting over the top of the door covering the open window. I roughly cut the shape of the window and then sewed the sides up to finish off the sleeve. I was able to sew the netting with a conventional sewing machine. By putting the sleeve over the door and putting a magnet strip across the bottom of the outside, the windows were sealed off from bugs.

To provide privacy, I traced the shapes of my car windows on an old sheet, cut out the shapes, and hot glued magnets along the edges. These magnets hold the window shades around the inside of the window on the metal door frame.

Bonus: To enable us to keep the side windows open if it was raining, I used old milk containers, duct tape, and sheet plastic to make a little rain cover over the door frame. The corners of the milk containers simply close in the door frame and hold the plastic out over the open window a few inches.

At the time of publication, we had begun in North Carolina, camped in the Badlands National Park (SD) and were headed to Glacier National Park (MT). We love the car, the 39 MPG, and the sleeping platform. Having separated storage areas has been wonderful to keep things neat throughout the road trip. We use the back compartments for shoes and "garage items" (camping stove, fuel, soaps, cleaning supplies), the hatches in the middle for our clothes, and the large storage areas where the seats used to be for gear and food.

Happy road tripping! I'll update more photos as the trip continues!